Confused about 1903 chambering issues with handloads

[kevin08]

Not sure if this is more appropriate here or in the reloading section but this is the situation:

I recently got everything I needed to reload my .30-06 brass and I'm using Hornady .308 150gr FMJBT projectiles that have a cannelure which is not in an appropriate place for the crimp to go to meet OAL requirements. I loaded a few dummy shells to check things such as OAL/chambering and what have you.

The load I'm going to talk about here had a case length (not trimmed) of 2.494" and the projectile seated to provide an OAL of 3.320." Very light crimp as that is what I've read to start off with.

I also recently acquired a Remington 03 off of a member here, and since I haven't had a chance to shoot it yet I figured I'd use it to cycle this dummy round. First thing I noticed was that it took some effort to fully lock the bolt in place, I have a Remington 03A3 that seats the bolt almost effortlessly, so it was something that caught my attention. Extracting the round didn't take anymore effort than I would have expected, but upon measuring the OAL length of the round after extracting, the projectile was pushed in and the OAL shrank. So I figure this means I should do a tighter crimp. I pull the bullet, resize the case, reseat and re-crimp with tighter crimp. Same OAL. Same experience when chambering and extracting, but this time it actually GREW to 3.349". Now I'm stumped. I tested cycling with a live HXP78 (OAL 3.325") and TW53 (OAL 3.323") round. The HXP round required slightly more effort to lock in, the TW53 was smooth. Neither's OAL is affected after being extracted.

I loaded up another dummy with the same specs and ran it through my 03A3 - perfectly smooth and effortless, OAL not impacted. I swap the A3 bolt into the 1903 and the same issue persists. Now I'm at a loss. I figure the chamber can't be short if the HXP/TW rounds both come out unscathed, the Hornady bullets are .308 at max diameter just like the military rounds, but it does SEEM as if the bullet is engaging the rifling and getting pulled out, but only the Hornady bullet and only on that rifle. Is it possible the M2 bullet begins to taper at a lower point than the Hornady and the Hornady is engaging the rifling prematurely? If so I guess that means the chamber is short just enough to grab the Hornady bullet without doing the same to the military M2 bullets.

Here are a couple of photos just to prove that I'm not insane, the first is the dummy load after extraction next to the TW53 round, you can see the crimp groove on the bullet just above the case mouth to see how far it got pulled out. The second is the OAL after extracting it from the 1903:

https://imgur.com/a/RXSDH4N

I've ordered a NOS 03 bolt body and a set of go/no-go gauges to check on the 1903. Should I be expecting to learn more from those that relate to this particular situation?

[USriflecal30]

Is it a new barrel with a minimum spec chamber? That's the way my new barrel on my 1917 is, and I can't load to the same length as my other .30-06 with not new minimum chambers. Same "problem" in my K-31, only the GP-11 bullet seems to fit in that chamber to full OAL, Hornady match don't even come close.

Bullet profile at max OAL can have an affect on chambering, not just every bullet will fit to OAL.

the OAL you measured after pushing the first round in, is probably the max OAL you can load to (with that bullet). The second round was longer because you smashed it into the grooves and then when you extracted it got stuck for a second before coming out with the case.

take a cleaning rod and with the bolt closed, drop in the rod and mark it where the end of the muzzle is. Next take said bullet and drop it into the chamber, just lightly hold it in place with a short rod. Take your cleaning rod and lightly touch the bullet, mark the rod again and measure the distance between your two marks. That's your max OAL with that bullet.

Maybe take that thing to a gunsmith and have him check the chamber with a chamber reamer to make sure you have a correct chamber.

Based on the fact new rounds sorta fed, it sure seems like you have a very tight chamber and/or minimal lead space into the grooves (which is fine, you just might have to load specifically for that gun).

[JimF]

Simple answer is, the throat of the ‘03 is shorter than the A3.

[kevin08]

Originally Posted by USriflecal30

Is it a new barrel with a minimum spec chamber? That's the way my new barrel on my 1917 is, and I can't load to the same length as my other .30-06 with not new minimum chambers. Same "problem" in my K-31, only the GP-11 bullet seems to fit in that chamber to full OAL, Hornady match don't even come close.

Bullet profile at max OAL can have an affect on chambering, not just every bullet will fit to OAL.

the OAL you measured after pushing the first round in, is probably the max OAL you can load to (with that bullet). The second round was longer because you smashed it into the grooves and then when you extracted it got stuck for a second before coming out with the case.

take a cleaning rod and with the bolt closed, drop in the rod and mark it where the end of the muzzle is. Next take said bullet and drop it into the chamber, just lightly hold it in place with a short rod. Take your cleaning rod and lightly touch the bullet, mark the rod again and measure the distance between your two marks. That's your max OAL with that bullet.

Maybe take that thing to a gunsmith and have him check the chamber with a chamber reamer to make sure you have a correct chamber.

Based on the fact new rounds sorta fed, it sure seems like you have a very tight chamber and/or minimal lead space into the grooves (which is fine, you just might have to load specifically for that gun).

It’s a 2-42 barrel which seems original for the serial # date, but it looks like it’s had little use. I’ll have to do that rod test and try another non-crimped dummy to see what it shrinks to, I didn’t record it but it was under 3.300”. I guess shrinking the OAL isn’t the end of the world but I am worried about increasing pressure if I were to shoot these loads through my M1s, I guess I’ll just switch bullets after I go through these 500...lol.

[kevin08]

After doing some checks it looks like a max OAL of 3.278" is what chambers easily without pressing the Hornady bullet in without a case crimp.

[Testelter]

I just had a somewhat similar situation with an 03A3 that I purchased. I had sized all my brass to fit the chamber on my M1. Turns out the A3 has a shorter chamber than my M1 resulting in a stiff closing bolt. After some measuring, I adjusted my sizing die to bump the shoulder back farther to accommodate the shorter chamber, I’ll just size all my brass to this length. As far as bullets go, lots of bullets have different base to tip lengths and corresponding base to ogive lengths and can require varying cartridge overall lengths.

Oh, and a tighter crimp to keep the bullet from getting pushed back into the case seems like overpreassure waiting to happen. Just an opinion

Tom

[78jeep]

Hornady's COL for that bullet is 3.185, so load to that. yes its short compared to M-2 ball, it will run just fine. I've used that same bullet, for me, they grouped better the faster I ran them. also no need to crimp. as noted above the throat is different in the 2 rifles. go/no-go will not tell you about the throat.

78jeep

[kevin08]

Originally Posted by 78jeep

Hornady's COL for that bullet is 3.185, so load to that. yes its short compared to M-2 ball, it will run just fine. I've used that same bullet, for me, they grouped better the faster I ran them. also no need to crimp. as noted above the throat is different in the 2 rifles. go/no-go will not tell you about the throat.

78jeep

I'm guessing that COL will place the cannelure right at the cartridge mouth? At almost 2/10" shorter than the comparable M2 OAL, I'm guessing I should not attempt to load those with 47gr IMR4895 like I planned, seems like that much decrease would have a tangible effect on the pressure, no?

Originally Posted by Testelter

Oh, and a tighter crimp to keep the bullet from getting pushed back into the case seems like overpreassure waiting to happen. Just an opinion

Tom

I've read the same and didn't intend to crimp originally, but am now at an impasse since dropping the COL will increase the pressure as well.

[78jeep]

yes shorter will change pressure. Hornady has 46.4 listed as max for 4895 with a Garand, but your shooting an 03. IMO, 47 is fine,47.5 or 48 would not bother me. you have a strong action. I've run 168 and 175g bullets with 47g's Varget ( similar powder).

work in your comfort zone, start low and work up.

78jeep

[78jeep]

not the same bullet, but it gives you an idea of a bolt gun load.

https://shop.hodgdon.com/reloading-d...726.1613571785


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IMPERIAL
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Your search returned 2 loads.
Case:Winchester
Twist:1:10.000"
Primer:Winchester LR, Large Rifle
Barrel Length:24.000"
Trim Length:2.484"
BULLET WEIGHT
150 GR. NOS BT

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Manufacturer Powder Bullet Diam. C.O.L Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
IMR IMR 4895 BUY NOW 0.308" 3.250" 49.0 2,856 49,400 PSI 53.0 3,009 56,700 PSI
BULLET WEIGHT
150 GR. NOS E-TIP

Starting Loads Maximum Loads
Manufacturer Powder Bullet Diam. C.O.L Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
IMR IMR 4895 BUY NOW 0.308" 3.300" 47.0 2,717 50,000 PSI 50.8 2,900 58,700 PSI