, how long is your A4 bolt

[Chuckindenver]

bolt setback on a 1903. is from the bolt being opened and slammed back into the ejector, if you look at the back of that lug, it may have a dent or divot from doing so, common issue, that dent, lets the bolt set back, and can give headspace issues, if another bolt works and gauges well, then id bet this is the issue.

[gigi79]

Thank you for the offer of help that you could give me at the time when you were traveling in the EU. And thank you all for your comments.

I am not looking for an A3 bolt body but an A4. The cocking lever is positioned well like the rear lock. This can only come from the front face of the bolt body. If I put an A3 bolt body, the headspace is OK: the GO gauge closes and the NO GO gauge does not close; for the A4, GO and NO GO close.

The photo is indeed a cheap body bolt but I have the A4 bolt body which is authentic. My A4 comes from WW2, left in a family barn in front of the Vosges front (by the 79th DIUS or the 501st RCC (2nd DB)).

I respect my armament and I do not slam a gauge when closing the bolt. I know how to use this equipment having been a specialist non-commissioned officer in armament for my unit.

I found a French importer and now I need to find a body bolt A4.

Thanks for your interest

[Chuckindenver]

bolt in your hand is not a genuine A4 bolt..

[gigi79]

Whatever you say, it's a bolt A4. This A4 has been in the family since 1944.

[1903Collector]

If your A4 has been with your family since 1944 then it cannot be a repro nor a non-USGI fake. It must be authentic!

Be aware that all Remington A3 bolts are marked with an "R" on the underside of the bolt handle. I would be surprised that a real Remington A4 bolt does not have the same mark. Ill have to get my A4 out of storage and look at my bolt, but I know it is authentic USGI.

In the states there are MANY owner-made/home-made/non-USGI bolts that were modified to work as an A4 bolt being sold as an "A4" bolt. Few of these home-made "A4 bolts" look identical to an authentic one and can be identified as non-USGI very easily. Authentic A4 bolts are hard to find here these days. Ive never held one of the the repros that were mentioned in one of the other comments, but Im told they are very good. They are not cheap either!

The comments about proper HS gaging were not made directly at you, but simply stated for all readers as many read posts looking for info and the person making the comment was just being thorough for the sake of all readers (or so I assume). Be sure to read the bolt design info myself and another person added to this thread. It helps to understand possible causes of HS issues if the design and interfacing features that control HS is known and understood. I just want to repeat, perhaps unnecessarily, that the overall length you were initially asking about has no relationship, nor provides any indication of the headspace with that bolt.

Just curious, but have you tried checking your A4 headspace with an A3 bolt of a rifle that has been proven to have good headspace? That is something I have done with other rifles when I was not sure about my HS results as it provided an independent result for comparison.

Good luck solving your issue.

[gigi79]

Yes, the bolt body has the R and all my parts have the R of Remington. Yes I have a nearly new 1903 A3 Remington and a copy A3 bolt body (poorly forged A4) acquired to test my M1903 A4. I acquired the M1903 A3 for my collection and to make another one for the A4. I checked the headspace and indeed, it is not good with the A4 slide but OK with the A3 slide. At first, I thought the chamber was HS but if the bolt body is OK...! I have no more doubts. I have to find an original A4 slide.

If all members who own A4s can photograph their original slide, cocking lever side, we will certainly have 2 models. One bent towards the rear (like me for an A4 model of the first series), another straight (ease of construction for the other series?).

[Chuckindenver]

whatever i say? maybe take some better pictures of what you have?

[Chuckindenver]

think iv handled a few A4s over the years

lets talk about headspace, beyond your bolt.. first, failing no go, isnt a end all, failing field reject is, are your gauges current made tools? forester or Clymer? or are they G.I.? is your gauge 1.496, 1.497 1.498 or 1.950? all of those are no go specs,
is the A3 bolt your trying an original Remington or SC bolt? or is it an R marked with R3 R4 or R6? as those are longer in the bolt head then a standard A3 bolt .
is the A3 bolt a CC marked bolt? most of those are known to be out of spec, is a BF marked bolt?
does the original bolt have bolt set back, as iv touched on before? dont know? look.
Forester and Clymer gauges are known to be undersized.
have you fired the rifle, after you gauged it? and used factory ammo? not reloads. what did the case head measure? did the primer back out? these are important questions..

[Chuckindenver]

bolt on the left has normal set back, bolt on the right has unsafe set back

[Chuckindenver]

were trying to help you out my friend, but you keep fighting it.. keep this in mind, iv worked on these for the last 35 years of my life, have worked and restored, 100s of these rifles. finding a genuine A4 bolt will be very hard, so many fake bolts, its easy to get burned.