03A3 to 03A4rgery - Anybody cut the A4 Bolt Notch in their A3 Reciever??

[Col. Colt]

I am working on assembling all the special parts and figuring out all the correct modifications to make an 03A3 into a "correct" - except for markings, of course - physically (and functionally) exact copy of an 03A4. As an older, heavier guy, this would be a match I could do well at!

One thing I have not heard much about is doing the Bolt Cutout in the side of the 03A3 Reciever to give clearance for the 03A4 modified bolt to close entirely, all the way, as all the originals were done. As I recall off the top of my head, the cutout I measured in a for real 03A4 last week was about .645 wide and on a 45 degree angle, with the back edge rounded to get rid of a sharp corner behind the bolt root, lining up perfectly with an original 03A4 stock.

If anyone has done this - how about sharing your experience? Any observations that might be helpful? CC

[Marine A5 Sniper Rifle]

There was no such cut out in the receiver. A real A4 bolt fits the receiver with no modification to the receiver.

jt

[da gimp]

There was no such cut out in the receiver. A real A4 bolt fits the receiver with no modification to the receiver.

jt


That was what I recalled too jimmy.

[Col. Colt]

The example gun I saw appeared to have it's original arsenal finish over the cut, and I pointed out the cut to the owner - he thought it was standard on all 03A3s, as well. I thought it had to be real, as the rest of the parts looked right, and his bolt would not completely close in my 03A3 uncut reciver. Curious..... CC

[musketshooter]

If you have to cut the receiver for the bolt, your bolt is incorrect.

[m1903rifle]

I have attached a picture of an original ( although sporterized ) A4 that has the notch. It's one of the early ones in the 3.42 Million range. Could it have something to do with the vintage, i.e. ,early or late?

[chuckindenver]

all genuine A4,s have a mill cut under the bolt root.

[Allen Humphrey]

I'm not sure if there are variations, but the one and only A4 I have held in my own hands has a notch under the bolt root.

[Marine A5 Sniper Rifle]

I repeat, any A4 bolt will fit any 03A3 without modification to the receiver. They all have the milled area shown in the pic. No modification is required (except the unique stock cut).

jt

[Johnny P]

http://i45.tinypic.com/242ts.jpg

[jgaynor]

The following lnk will take the viewer to a series of recent CMP auctions of A4's and A4 receivers. The descriptions have good close up pictures and the entire s/n range of a4's is covered

http://cmpauction.odcmp.com/search.asp?searchtxt=1903A4&searchtype=0&view=&show=closed

I agree all authentic A4's recieivers have the relief cut for the bolt handle root.

Regards,
Jim

[Dan in NY]

Here's #34235xx. Has the bolt cut.., as does my 4,99 mil A4.

great link above, Jim...very informative..


http://img.photobucket.com/albums/v168/218bee/316x5pg.jpg

[chuckindenver]

A5 is right. notching the action is not needed if your using a real A4 bolt..if your using a sporter bolt? all bets are off

[Col. Colt]

While it may (or may not) be generally true that "most" A4 bolts work in "most" 03 Actions without the cut, my friends A4 bolt (from a REAL A4) would not completely close in my unmodifided A3 action without the bolt root cut, even with a genuine, US GI A4 cut stock installed.

And with Remington, by 1943 only doing "Essential Operations" to the 03 and 03A3 to speed up and cheapen production (no lightning cuts on the rear sight base of a Remington 03, for example) why on earth would they add an additional, unnecessary cut to the reciever that they did NOT have to?? Not only do they do the cut for the bolt root, they had to finish the edge of the reciever with a curved corner. If making the bolt correctly completely solved this problem, how come Remington set up to do this cut on three different runs of rifles? If it wasn't needed, why was it done? CC

[Randy A]

Col.
Good question, but I for one have installed an original A4 bolt in a few A3's and they do clear without the cut (no, I didn't leave them there). So I got out the calipers and discovered (I have quite a selection of bolts) that the A4 bolts have a longer root than any other 1903 series bolt handle (the distance from the body to the corner of the bend). With the exception of one A3 bolt handle type which I strongly suspect is the bolt type used to make A4 bolts. I believe, on my A4 it would clear without the cut I can only speculate that there was the one or two (like the one you ran into) exceptions that mandated the cut.

[Jim In Oklahom]

My '03A4, No. 49922xx, received from the DCM in 1964, has a 1/16 inch deep cut in the receiver to give clearance for the bolt.

[Randy A]

Any original A4 I've ever seen has them!

[Col. Colt]

OK, guys - upon further research, it appears we did not answer the most important question. Doing the final assembly of my 03A4gry, after getting my real 03A4 bolt back from Chuckindenver for parkerizing, I noticed the bolt does not seem to close all the way.

In every single standard 1903 non-scoped Action I know of, the safety lug is all the way down on the reciever rail when you close the bolt. Period. It is resting ON the rail, touching firmly. When I install my real 03A4 bolt in my standard 03A3 reciever, even with a light bevel like the photos, if not quite as deep, the safety lug does NOT and CANNOT touch the rail, indeed, the bolt appears to be a few degrees from truely "locked". Is this safe? Or does it matter? I want my "03A4gry" to be mechanically the same as a real one. And safe.

The question I should have asked last November - Those of you with REAL 03A4s - does the safety lug rest on the Right side rail, touching it - or is it held above it a sixteenth or two? What is the width of the remaining rail to the edge of the bolt cut in the reciever? I am trying to figure out how deep I might have to cut the reciever bolt root cut to get the safety lug onto the rail. Thanks in advance. CC

[Cecil]

I'm not sure what's going on with your rifle but over the years I have assembled 3 wanna be A4's. I used USGI parts to assemble all 3 including original stocks. Each one was a drop in with no modification. Each one was built on a previously drilled and tapped receiver.

[Col. Colt]

Mine iis also all GI parts, to include the stock. Built on an 03A3 that was already drilled and tapped for the Redfield Jr. Mount. Just like yours.

The question is - and I think this can only go to owners of verified, for sure real 03A4s with their original bolts - does a Normal 03A4 bolt safety lug rest on the right reciever rail - assuming no stock interference? Or is it a sixteenth or two above it?

What I'm trying to say is that the "conventional wisdom" seems to be WRONG here. Conventional wisdom as firmly told to me is that the bolt root clearance cut done to EVERY 03A4 during WWII was done just for fun, Remington had lots of extra milling machines, cutters and workers during WWII and lots of time to do machining that was Totally Unnecessary. That means that my stock, 4.1M 03A3 Action must have something special about it. Or my verified original 03A4 Bolt is also somehow "different" than the other forged 03A4 bolts made on the same tooling. Because my safety lug is being held off the rail by the 03A4 bolt handle root contacting the reciever.

I'm sure that the gun will fire, and I doubt if it is hazardous. But is it RIGHT? I like bolts completely locked, myself.

Please, someone with a Real 03A4 - answer the question. Better yet, those of you with a verified "real 03A4" Bolt, try it in a standard 03A3 and let me know if it closes to the rail. CC

[Cecil]

Mine iis also all GI parts, to include the stock. Built on an 03A3 that was already drilled and tapped for the Redfield Jr. Mount. Just like yours.

The question is - and I think this can only go to owners of verified, for sure real 03A4s with their original bolts - does a Normal 03A4 bolt safety lug rest on the right reciever rail - assuming no stock interference? Or is it a sixteenth or two above it?

What I'm trying to say is that the "conventional wisdom" seems to be WRONG here. Conventional wisdom as firmly told to me is that the bolt root clearance cut done to EVERY 03A4 during WWII was done just for fun, Remington had lots of extra milling machines, cutters and workers during WWII and lots of time to do machining that was Totally Unnecessary. That means that my stock, 4.1M 03A3 Action must have something special about it. Or my verified original 03A4 Bolt is also somehow "different" than the other forged 03A4 bolts made on the same tooling. Because my safety lug is being held off the rail by the 03A4 bolt handle root contacting the reciever.

I'm sure that the gun will fire, and I doubt if it is hazardous. But is it RIGHT? I like bolts completely locked, myself.

Please, someone with a Real 03A4 - answer the question. Better yet, those of you with a verified "real 03A4" Bolt, try it in a standard 03A3 and let me know if it closes to the rail. CC

I have an original A4. What I don't understand is exactly what you want to see. I'm a deck ape with guns, not an armorer. I have though owned eight real A4's.

[Col. Colt]

Thanks for responding, Cecil. When I started this build, from 03A3 to 03A4 I went and looked at a friend's real 03A4. I noticed the bolt root cutout on his A4 - and none on my ordinary 03A3 reciever. After messing around with two replica bolts I bit the bullet and bought a Real A4 Bolt (Wow, $$$). Installing it in the A3 action, I noticed that, unlike every other M1903 Springfield I have ever handled, the bolt appears to stop, just short of closing. I assumed it was the bolt handle cutout in the stock until I took the barreled action out of the stock - nope, still would not turn all the way down and locked like any regular non-scoped 1903.

So, looking at the right side of your real A4 action, look at the bolt's safety lug directly in front of the reciever bridge. Is it resting on the right reciever rail - or not? I was told firmly here that the A4 Bolt was all you needed to convert an A3 to an A4 - and I'm sure it will fire - but shouldn't the bolt be turned all the way down, safety lug touching the rail? I can see that mine will not do so without machining the reciever - because it is putting a shiny line on the underside of my bolt's root. I just want to know for sure how a real A4 looks before I go to a machinist. CC

[blackhawk2]

Col. Colt With the bolt handle in the down position, the safety lug is resting on the receiver rail...regards

[Col. Colt]

Thanks so very much, Blackhawk. I need to see if I can borrow a real one and get accurate milling dimensions. I don't want to fire it without the locking lugs where they should be. CC

[Darreld Walton]

I've tried to fit several "real" A4 bolts into varying s/n range A3's, both Remington and SC over the years, for S&G's, and no, they are NOT a universal fit into all A3's.
In the rifles I've owned and handled, the bolt safety lug does, indeed, rest on the rail when the bolt is closed. While I suspect that headspace would be just fine if there is a small gap between the rail and the safety lug, it would be seriously wrong to make a blanket statement saying so. In all cases where there is a question regarding such a thing, it's best to obtain a set of headspace gauges, and check 'er out!
If the headspace is okay, the next thing to check is that the firing pin protrudes far enough to give consistent ignition. I say that because if you take a look at the camming surface in the bolt, and the lug on the striker rod, it really needs to be fully in the bottom of the cut for consistent firing pin protrusion. If the bolt won't close all the way, the cam on the striker rod will hit the camming surface in the bolt and keep it from going fully forward.
BTW, I too, thought that shooting prone, over the bags, would be THE match for this old, fat man......but when the rifle recoiled, I looked like a rocking horse, and lost time trying to get back into firing position.............

[Col. Colt]

Thanks for the confirmation, Darreld. I've been doing this a long time (although not as long with 03's) and I was hoping I hadn't completely lost it! I thought about the effect on the firing mechanism, too, but it looks pretty close and that might or might not be a factor - depending on tolerance stackup, of course.

The more time I spend with these fine old rifles, the more respect I have for the men who used to master them - and use them to such good effect on our enemies. Using a rifle well is a total integration task - Mind, Body, Spirit. I fear that the necessary Concentration has been largely lost, of late, for our more current generations. When you think about how "tuned in" a soldier had to be to his weapon and the environment in the middle of a battle in order to still score hits it becomes all the more impressive. We have some wonderfully skilled military personnel today, and equally as brave - yet riflery is harder to practice with a carbine!
Again, Thanks, CC

[Col. Colt]

Note: If you have an 03A4 replica using an original A4 Bolt and an unmodified 03A3 reciever, you need to check that the safety lug rests on the right reciever rail. This may also apply to gunsmith manufactured 03A4 bolts, but it definitely is a possibility if you have an original bolt. Or it may not even be a problem for your combination of parts. But I recommend you check.

UPDATE: 03A4gery completed!! After a careful evening with the rifle action in a vise, the stripped original GI 03A4 bolt (beautifully reparked GI color by chuckindenver - Thanks, Chuck!), a Dremel tool and some lipstick (!), my original 03A4 Bolt now closes completely, with the safety lug of the bolt resting on the right reciever rail. Originally, with the original 03A3 reciever and a very light angled cut, the bolt was about .020 short of closing, measuring under the safety lug. Using red lipstick in place of Dychem Blue on the bolt root, it was easy to see where the bolt handle was touching the reciever.

My 4.1 million Remington reciever/GI 03A4 bolt combination required removing material from the reciever directly behind the rear reciever bridge, the width of the bolt handle (plus a little) with a line basically from the top edge of the right side reciever rail, angling downward until you match up with the GI bolt notch cut in the stock. Your mileage may vary - I went very slow, taking off a thousanth or two, starting from the bottom edge of the reciever rail and working upward, until the bolt closed completely. I coated the bolt handle root with the "Hooker Red" lipstick after each attempt, until nothing was "kissed" by the lipstick anymore.

Now I find there is still a very slight interference with the GI 03A4 Scant Stock's 03A4 bolt cutout near the forward edge - maybe .008 from fully closing. Probably swelling over time made it a hair too tight - it's a very rough cut and obviously well used Scant GI 03A4 Stock, with a square magazine cutoff cut and a "boxed SA" and circle P Proof marks. Minor, but I will correct it before I take it to the range.

I did notice a definite difference in the "solidness" and steadiness of the bolt in full lockup - Safety Lug down on the Right Reciever Rail vs. any point short of that. With the bolt being held up off the reciever behind the rear bridge, it seemed that the locking lugs did not address the reciever "squarely" and the bolt "rocked" a bit when you manipulated it back/forth or up down. I think this modification is worth doing, so the bolt locking lugs seat evenly when the rifle is fired. One less thing to "move funny" when the rifle is fired, one less variable for accuracy. I will furnish pictures if/when I feel more motivated - sleepy Labor Day Sunday! CC

[pelago]

If you have to cut the receiver for the bolt, your bolt is incorrect.

this is true, during last CMP competitions at Camp Perry there were hundreds of sniper rifles and many many of them were true original 1903A4's not a one had a cut in receiver.

I have seen many A4's none had cut

[Col. Colt]

Revisit the first two pages of this post and look at the pictures. Or look at the link in jgaynor's post there : http://cmpauction.odcmp.com/search.a...w=&show=closed

These are CMP auction site photos of Many 03A4s they have sold. Pictures don't lie. ALL HAVE the CUT!

Warmly, CC :)