SIA Enfield .45 Conversion Kit.

S.I.A. Enfield .45 Conversion Kit.
An ideal conversion for anyone desiring a relatively quite
gun that is inexpensive to shoot, with minimum recoil.
Good for target shooting, but still powerful enough at
ranges under 150 yards for most small to medium game
hunting or self defense.
An excellent choice for those who would like to have a
rifle in the same caliber as their hand gun.
A great gun for youth or ladies to step up to from the .22
before graduating to high power rifles.
A superior platform for suppressor use where legal.
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Special Interest Arms
1422-A Industrial Way
Gardnerville, NV. 89410
(775) 782-4342, Fax (775) 783-4867
http:// www.specialinterestarms.com
DRAFT COPY
Call or e-mail with questions.
am still working on the final version of this manual.
All content copyright 2008 by S.I.A.
This is the basic kit.
It includes the barrel, magazine adaptor, magazine, and
ejector assembly.
The steel parts are normally supplied with a black
Parkerize finsish.
The magazine adaptor is hard anodize coated.
The magazine adaptor.
The adaptor arrives preassembled, except for adjusting the latch piece
(The tapered aluminum block with two holes, at the rear of the adapor), no
adjustments or disassembly should be required.
The inverted "L" shaped stainless piece is the magazine release.
Once installed it is recommended that you leave the adaptor in place
unless it must be removed for cleaning.
Reloading should be done by removing only the 1911 type pistol
magazine.
Front sight.
A Williams® type sight base can be fit to the front of the barrel after
headspace, or S.I.A. can provide a barrel modified to use a modified
Enfield sight on request.
Contents.
1. SAFETY FIRST!
2. Choosing a gun to convert.
3. Tools needed to complete the conversion.
4. Disassembly of the host Enfield.
5. Getting the old barrel off.
6. Setting headspace.
7. Open up the barrel channel.
8. Modifications to Enfield components.
9. Final assembly.
10. Loading and firing.
11. Barrel break-in, hints for accuracy.
12. Maintenance.
FAQ's
Trial fitting of parts.
Please read the complete instructions before starting this
conversion.
Make all necessary modifications to the Enfield parts,
headspace witness marks, and adjust the latch for the .45
magazine adaptor before final assembly.
Do your "dry run" assembly of the parts without using any loctite. When everything is correct, disassemble the parts and
reassemble each component useing the appropriate tools,
gauges, and thread sealants.
1. SAFETY
A. Never have any live rounds in the work area!
Headspace MUST ONLY be set with dummy rounds or
gauges.
B. Do not convert any Enfield unless it has a working
safety.
C. Do not convert an Enfield that has any issues with the
sear, trigger, bolt, extractor, etc. until they are corrected.
D. Check for yourself that the gun is unloaded.
E. Wear safty glasses when grinding parts or test firing.
F. Please wear hearing protection when shooting.
G. Clean the barrel before shooting.
H. Follow directions and safety warnings for any
chemicals you use during the build.
2. Choosing a gun to convert.
This conversion can be made to a No. 1 Mk. 111, or to any variation of the
No. 4 or No. 5 Enfield.
Here are the pro's and con's of each model type.
The No. 1 guns are usually a little less expensive to buy.
The disadvantages of the No. 1 's is that they are usually much older and
more worn than the No. 4 or No. 5 guns.
Converting a No. 1 gun may require some grinding of the inside of the
trigger guard in order for the .45 adapor to fit properly.
The bolt of a No. 1 may be noticeably loose in the bolt guide, this can
make reliable feeding or extraction more difficult to achieve.
Spare extractors or bolt heads for the No. 1 actions are harder to find and
buy.
The No. 1 guns mount the rear sight on the barrel, forward of the action,
this gives a shorter sight radius.
The No. 1 guns have round sided receivers, which often makes scope
mounting more difficult.
There are relatively few accessories made for the No. 1 action.
If you plan to convert a No. 1 type Enfield, try to ensure that you get one
with a fairly tight action.
No. 4's
No. 4 or No. 5 guns or actions cost a little more, but they were still being
made up to the early 1960's.
Most No. 4's have good tight actions, but do be sure to check that the bolt
guide rail is not damaged.
Most spare parts for the No. 4 type actions are plentiful and inexpensive.
The selection of after market scope mounts, custom triggers, stocks, and
other accessories for the No.4 or No. 5 actions is excellent.
The rear sight is mounted at the rear of the receiver, giving a superior long
sight radius.
Most original No. 4 or No. 5 Enfield's come with a factory micrometer type
adjustable rear peep sight.
This is very useful to compensate for the .45's ballistics!
The No. 4 or No. 5 receiver is flat sided, this helps with fitting some scope
mounts or after market peep sights.
The late No. 4 Mk. II has a trigger that is hung from the receiver, this is the
most desirable model for precision shooting.
Enfield .303's are regularly imported in large numbers by several
companies. At last check they were available wholesale at around $150$175.
They are also common at gun shows and pawn shops.
Good clean all original guns can be expensive collectors items.
The gun you will want to buy is probably one that has been sporterized
several years ago, or "FTR" before being sold as surplus.
Since you are replacing the barrel, it will not matter if the original bore is
bad, but it might save you some money on the purchase.
Always get a gun with a WORKING safety!
3. Tools needed to complete the conversion.
A. Set of flat blade screwdrivers.
B. Action vise.
C. Barrel wrench.
D. Sturdy mounted bench vise.
D. Wrench for barrel nut.
E. Grinder or File to modify the extractor.
F. #29 drill.
G. 8-32 tap.
H. .45 Dummy round, or head-space gauges.
I. Blue "Loc-Tite" thread sealant.
4. Disassembly of the host Enfield.
The most difficult task will be removing the old barrel.
Unless you are refinishing the entire gun, most of it does not need to be
dismantled.
You do need to remove the fore-stock to remove the barrel.
You will have to remove the bolt and extractor.
5. How to get the old barrel off.
It may help to soak the action and chamber end of the barrel in penetrating
oil for a couple of days.
You will need a very sturdily mounted bench vise.
You must support the receiver in order to prevent warping it while
unscrewing the barrel.
Action wrenches are available from gunsmith supply companies such as
Brownell's. $70-$120.
Alternately, if you are only doing one conversion, you may be able to
make a receiver clamp from hard-wood or aluminum.
You want to hold the reciever tight without crushing it.
A pair of blocks cut with an internal shape similar to the reciever exterior
should grip the area around the barrel base.
Clamp the receiver in a vise, grip the barrel with a barrel wrench, or if you
are not concerned with saving the old barrel, a large pipe wrench may be
used.
The barrel is a 1-14 right hand thread, once you get it to budge it usually
comes off fairly easily.
If it will not unscrew, or the action cannot be held tightly enough, see
below.
-
It is better to spend a few dollars as instructed here than to ruin
your receiver!
How do I get my old barrel off when it's REALLY stuck!
If you do not have access to a lathe, a local machine shop or gunsmith
can handle this for you at a nominal cost.
Many Enfield barrels are extremely hard to remove, they have been on
the gun for about fifty years!
We find that the easiest way to get them off the receiver is as follows.
A. Strip the action out of the stock, remove the rear sight, and all small
parts which might come loose while the action is spinning in a lathe.
B. Strip the bolt assembly, you will need a firing pin removal tool.
C. Insert the bolt body into the barreled action.
D. Mount the barreled action in a lathe with a "swing" of 9" or larger.
E. At the receiver end place the firing pin hole of the bolt body on a live
center mounted in the tail stock.
F. Chuck the barrel in a self centering three jaw chuck.
G. At very low speed turn off the barrel shoulder (Chamber area just in
front of the receiver) to 1" diameter using a thin blade parting tool.
Wear safety glasses!
H. This will relieve pressure on the barrel shoulder and threads, the
barrel should now unscrew easily.
Since the barrel shoulder has been machined back the barrel is now
scrap, this is not a problem, you are fitting a New .45 barrel.
6. Headspace the new barrel.
1. Throughly clean the receiver, particularly the threads where your new
barrel will screw in.
If necessary they can be "chased" with a 1-14 tap.
2. Remove the extractor from the bolt head.
You will have to modify it later, as described in step ??
3. Replace the bolt head on the bolt, put the bolt assembly back in the
receiver, and close it all the way.
4. Insert a dummy round or "GO" gauge into the barrel chamber.
5. Screw the barrel and it's lock ring into the receiver until it is stopped by
the bolt face.
6. Cycle the bolt to ensure that the dummy round or gauge is fully seated
in the bolt face and chamber.
If the fit is now loose, tighten the barrel as above and repeat the check.
7. Mark the barrel and receiver with a "Witness mark" for reference.
8. Remove the dummy round or "Go" gauge.
9. Unscrew the barrel 1/8 to 1/4 of a turn.
10. Insert a "No-Go" gauge into the chamber and try to close the bolt.
A. If the bolt will not quite close your headspace is OK.
Make a new witness mark for final assembly.
B. If the bolt does fully close your headspace is too great, you need to run
the barrel into the action a little more. Repeat steps 5-10 until heaspace is
correct.
11. Once headspace is correct remove the barrel and lock ring, add a
drop of "Blue" Lock-Tite® to the threads.
12. Using your witness marks, screw the barrel into the reciever until it has
the same headspace as before.
Quickly check your headspace, before the Lock-Tite® sets up.
13. Put a drop of "Blue" Lock-Tite® on the thread, tighten the lock ring
against the receiver face with an AR-15 stock wrench.
If you are not satisfied with the location of the lock ring's slot, you may
carefull grind the back side down a little at a time until the slot rotates
below the line of the stock.
You should check these steps before using Lock-Tite®
This is why trial fitting of all components is a good idea.
14. Now you may assemble the rest of the gun.
If you have any additional questions on
headspacing please contact S.I.A. or a qualified
gunsmith. Headspace is simple for a gunsmith.
7. Enlarge the barrel channel in the stock.
The .45 bore is significantly larger than the original .303.
This requires that the .45 barrel exterior must also be a little larger, so it will
be necessary to open up the barrel channel in the stock.
This can be done with a hand grinding tool and burr, or round wood rasp.
Once the channel is close these tools should be followed with coarse and
fine sand-paper wrapped around a suitable piece of wood dowel rod.
8. Modifications to Enfield bolt head, extractor and installation of
the ejector in the receiver.
A. Drill and tap receiver for the ejector stud.
Use a sharp #29 drill and a 8-32 tap.
Locate the hole1.25" back from the square edge of the barrel trunion, and
.788" from the bottom of the receiver.
You want the plunger to sit in the middle of the bolt guide, about 1.25" from
the end of the barrel.
The inside and outside surface of the receiver may be quite hard, you must
be careful not to break the tap!
This usually happens just as the tap begins to show inside the receiver.
Screw the plunger in until the threaded body just touches the
bolt, then back it off 1/8 of a turn.
Ejector Plunger as seen from inside receiver
Note that only plunger button
extends into path of bolt.
The spring loaded plunger has a dab of lock-tite, once it is
adjusted you can use the cover knob as a lock nut.
B. Bolt head
Grind a small 45° angle on the left side of the bolt head to depress the
ejector plunger when the bolt is pushed forward.
This also creates a space for the ejector pin to get behind the cartridge
case when the bolt is pulled back.
Grind off just enough to depress the plunger without blocking the bolt. Do
not force the bolt past the plunger, this can damage the ejector pin.
C. Extractor
Carefully grind the end of the exractor flat to clear the end of the barrel.
You want to end up with just enough space to clear the end of the barrel.
This is usually about .055" from the flat at the back of the extractor.
You need to releive the underside of the extractor arm so that it will put
suffiecient pressure on the case rim. Grind it to .055" just where it contacts
the bolt head.
Adapter catch
Catch adjustment screws
1911 Mag catch
1911 Magazine adapter
9. Final assembly.
1. Your barrel and headspace should already have been set up, checked,
and finalized.
2. Your extractor and ejector modifications and installation should already
be complete.
3. You may now put the action back into the stock.
4. Loosen the two alien screw that hold the magazine adaptor into the
magazine catch.
5. Push the .45 adaptor body firmly into the Enfield receiver until it stops. It
should be resting against the flat surfaces machined into the bottom of the
bolt guide.
6. Push the adaptor catch up until the bottom edge passes the original
Enfield magazine catch.
7. Now push it down until it is stopped by the original Enfield magazine
catch. Tighten the locking screws.
8. Remove the adaptor body, push it back in like an original magazine. If
your adjustment is correct it will now be a firm fit in the reciever.
9. Verify that the adaptor is secured by the latch, it should not be able to
come out without pushing on the Enfield magazine release lever.
10. Insert an empty Colt® 1911 type magazine into the adaptor. It should fit
and latch with a firm upward push.
11. You should not need to modify your stock or trigger guard. If you have
an exceptionally tight trigger guard it may prevent the latch from moving
enough to release the magazine. The catch is stainless steel, you may
grind a little metal away from the outside top edge to gain more movement.
When properly fitted the magazine should be a "Drop-Free" fit when the
lower end of the lever is pushed in.
12. Do not force the magazine into place, the first few times the magazine
is inserted it may be necessary to slightly release the catch. Once the parts
have been operated a few times the magazine should automatically push
the catch out until it latches in the magazine retaining notch.
10. Loading and firing.
1. Depress the stainless right side lever to remove the 1911 magazine
from the Enfield adaptor.
While the lever is depressed, pull the magazine down until it is clear of the
adaptor.
2. Push rounds into the 1911 magazine from the front edge and downward
at the same time until full.
many magazines work best with one round less than full capacity.
3. Insert the loaded magazine into the bottom of the adaptor, push up until
it latches in place.
4. Push the bolt smartly forward in a single motion, push the handle down
to lock the action.
5. The action is now cocked and ready to fire.
If you do not intend to shoot immediatly, engage the safety by rotating the
lever to the rear.
When ready to fire, disengage the safety by pushing the lever forward, aim,
and smoothly squeeze the trigger.
It is recommended that you do not remove the adaptor from the action
unless truly necessary for cleaning.
Too frequent removal may wear the adaptor latch unnecessarily.
11. Barrel break-in, hints for accuracy.
Your Enfield .45 kit comes with an air-gauged match grade Montana
Rifleman® precision barrel.
In order to get the best accuracy and longest life from it we recommend
that you "Season" the barrel before extensive shooting.
This is really an easy task, it just takes a little patience.
After the gun is fully assembled and all functions have been double
checked.
1. Load the magazine with ONE round.
2. Chamber and fire ONE round, extract the spent case, remove the
magazine, and clean the bore.
Examine the primer of the first couple of rounds to verify that the firing pin
does not protrude excessively.
Repeat firing single rounds at least five times.
3. Load the magazine with FIVE rounds, fire and extract them, remove the
magazine and clean the bore.
Repeat at least three times.
4. Your barrel is now "seasoned" and ready to use normally. It is a
precision instrument, cleaning after every shooting session, or
occasionaly while shooting if you shoot a lot, will help to maintane it's
accuracy for many years.
12. Maintenance.
Your Enfield .45 kit was manufactured using the best possible quality
materials and components.
Your completed gun is a precision instrument.
Please follow standard cleaning practices after each session of shooting.
The .45 barrel is carbon steel, it is rifled to air gauged match quality.
The exterior is a black parkerized finish unless you have applied an
alternate finish.
It should be lightly oiled after cleaning.
Cleaning from the breech end will protect the muzzle crown.
The magazine adaptor is hard coat anodized aluminum, it is scratch
resistant, but not scratch proof.
It may be cleaned with normal gun cleaning solvents, or mild soap and
water, then dried with a soft cloth.
The magazine catch is stainless steel, it is rust resistant but not rust proof.
A light coat of gun oil is recommended.
The small coil spring under the magazine latch should be treated to an
occasional drop of oil.
The magazine catch should not normally be removed for any reason, it
can be replaced if necessary by driving out the stainless 1/16" roll pin.
The basic Enfield action and bore should be cleaned in the same manner
as any other bolt action rifle.
Most Enfields have a black parkerize finish, some may have all or part of
the action overlayed with a coat of black paint.
Parkerized surfaces should be treated with a light coat of gun oil after
cleaning.
"FAQ's"
Why use the Enfield as a donor?
The Enfield is reasonably inexpensive as a donor gun, it has a strong
and well proven action.
It also has a factory detachable magazine, so converting to our .45
magazine adapter is relatively simple.
Where should I look for an Enfield to use for conversion?
Enfield's have been imported in large numbers over the last several
decades.
Many of them can be found already "sporterized" at gun shows, pawn
shops, or garage and estate sales.
Recently imported guns are currently available from several wholesale
outlets.
Many gun shops will have a couple of .303 Enfield's on hand, try to
buy a gun you can examine in detail before purchase. Since you intend
to replace the barrel you may get a gun cheap if it has a poor bore.
Why not use another gun, like a Mosin-Nagant or Persian Mauser?
Those guns would be much more difficult to do, and would end up
being more expensive.
The Mosin-Nagant has no magazine well, the Mauser has a floor plate
and internal magazine. Besides, I like Enfield's!
Aren't you destroying valuable collector guns?
No, the guns to convert have little or no collector value. They are
usually sourced from foreign military surplus, they have been "FTR"
and then sold to third world countries by the shipload.
Can I change my gun back to .303 British?
Yes, but why would you? It would be cheaper to just buy another
Enfield .303!
The receiver is only modified with a single small hole, but the barrel,
bolt head, and extractor would have to be replaced.
How powerful is the .45 acp round, how far can I shoot accurately with
the converted gun?
The .45 Automatic Colt Pistol round was originally intended for pistol
use, it is excellent on targets, or game up to White -Tail deer size, it is
very accurate to 50 yards, and reasonably accurate to 100 yards.
It will reach much further, hitting a target at long range will take more
skill at "Kentucky Windage".
Can I put a scope on my Enfield .45?
All standard Enfield accessories should work with the "Enfield .45". We
suggest a 2.5-8, 4X or 6X scope in 32-40 mm objective lens.
What magazines fit the Enfield .45?
Any good quality 1911 Colt type single stack magazine should work.
You should be aware that most states limit hunters to 5 rd. magazines,
others have bans on magazines holding over ten rounds.
What scope mount works best?
There are several scope mounts available, but most of the inexpensive
"No-Drill, No Tap" mounts are not very steady.
We recently tried out an "S&K" mount, finding it to be much better
than several other "instant" mounts, at a reasonable price.
The Cad-Tecnik (SP?) also seems to be a good choice.
The "William's"® #71 scope mount screws directly to the receiver, it is
very solid, and allows the scope to be used as a "Quick Detachable"
type so that scopes may be interchanged, or iron sights may be used if
desired.
Is the completed conversion still a C&R gun?
Under our understanding of the law it is not.