first carbine unboxing

[W5USMC]

Ahh, I have not looked on reddit, but more importantly Charlie, Welcome Back!!!!

[ssgross]

I had my son at the range with me tonight...the main purpose of the trip was to zero our 1873 trapdoor. But...with the extra body to chase brass, we took this carbine too.
We were shooting PPU, 110gr soft points. Reportedly 2001 FPS. It's cheap ammo, and I knew better than to expect too much from it. Had my labradar with me, and here are the results across a box of 50
Avg. MV: 1945
min 1868, max 2038
SD 40.8

With the sight all the way down, and zeroed for windage, at 25 yds we were ~4 inches high on average. Horizontal spread was nill, but we were stringing vertically a total of 6 inches or so. With the target (8 1/2 by 11 sheet of paper) at 100 yards, and aiming at the bottom of the page, we scattered all over the target, but seemed to hit the paper with regularity.

Now, I purchased 3 brand new still in the grease wrap USGI magazines for this rifle. They all jiggle something fierce in all directions when in the rifle. We were loading groups of five, and for the first 6 groups, every 3rd round jammed - no failures to eject, and the ejection pattern was a consistent 4 o'clock. Once the barrel warmed up, they still kicked out at 4 o'clock, but went much higher in the air, and 3 out of every 5 rounds were jamming.

Every failure to feed was the same. I think the magazine sits too low (lots of vertical play), which makes the angle at which the nose of the round kicks up too steep, and the round wedges in the mouth of the chamber, halfway in. If I pull back slightly on the op-rod, and relieve the forward pressure, the next round in the mag pops the base of the jammed round up and all is well again.

If I'm not completely off in left field with my hypothesis, can someone recommend a better magazine? I'm sure the accuracy will greatly improve with some handloading and better fitting magazines. On a good note, we only lost 2 out of 100 pieces of brass

[browningautorifle]

can someone recommend a better magazine

Maybe the mag catch? I've never had problems with any GI 15 rounders, unless yours are GI 30s which are scarce. If the mags are low, which it sounds like...and they're new? Try a new catch. Does it feed OK when you have a hand under it holding it up? Try that...

[USGI]

I've never tried firing soft points from my carbines. They were designed to shoot FMJ's. I've heard that some guns will run the SP's and others "hiccup" on them. PPU is generally rated pretty high on gun forums that I've visited, just don't know whether their SP's are known to give problems in a carbine. Another thing along the lines of what Jim said about holding up the mag with your hand - if that helps, take a look at the "nibs" on your new mags to make sure they aren't beginning to shear off already. I had that happen on (2) brand new KSG 15rd mags the first time I used them. Some manufacturers didn't get the metal hardened properly early on - later ones worked fine. Hope you get it figured out - don't give up on it too soon! Marlin barrels didn't have the greatest reputation, but you've already done a pretty close inspection and cleaning on it. - Bob

[browningautorifle]

take a look at the "nibs" on your new mags

Only reason I didn't go there first was his description of "New" mags.

[ssgross]

yep. they have only been in and out of the rifle maybe 3 times each.

[Bruce McAskill]

PPU bullets all seem to be a bit undersized. At least a full thousand smaller then anyone else. This may be why you spreading of your groups. .308 diameter is .307 in reality. I have found this with their pistol bullets as well as their rifle bullets.

[jimb16]

Carbine barrels had a spec of .3075. If those bullets are .307, then they are undersized and will contribute to accuracy problems.

[Rockandroll]

Your barrel should be in good shape as no one (military) made .30 Carbine corrosive ammo.

[ssgross]

Your barrel should be in good shape as no one (military) made .30 Carbine corrosive ammo.

it is. I think I have borescope pics above somewhere. I'll troubleshoot the feeding issue this weekend by inspecting the magwell and catch closer, and slug the bore while I'm at it. I'll remove the firing pin and see if I can reproduce the feeding issue manually.