Trouble with 7.62 NATO reloads

[omface@yahoo.com]

I just dove into a scar 17 platform. After shooting all of my factory ammo I started to reload. I noticed that the base was a little expanded but barely. Only 1/3 of the rounds chamber the others make is just far enough for the bolt to begin locking but not complete it so obviously the base isn't chambering. The rounds that do chamber fire without a hitch. Has anyone had this problem reloading 7.62/308? The brass was RP so I'm thinking cheap brass.

[CavReconScout]

What dies are you using?

[omface@yahoo.com]

Rcbs dies. And the sizer is a full length.

[ace4059]

Was this brass fired through the scar or is it range collected brass?
Sounds like it needs to be sized with a small base sizer.

[Tzed250]

When you adjusted the FL die did you screw it down till it contacted the shell holder then give it ¼ turn more before setting the lock ring?

[shootist~]

What others have indicated - it sounds like your FL sizer die is not adjusted properly.

I'm using a Redding .308 sizer die for SCAR reloads with no issues, but I also use and like RCBS dies. Mine is even backed off a little to reduce the shoulder setback, but it still makes at least light contact with the ram.

All my brass is from my rifles, fired either in FALs or the SCAR. BTW, with my die setting my SCAR reloads will not easily chamber in a .308 bolt gun.

You might see something by measuring the case diameter of your problem reloads just above the web. Compare that to a few fresh factory rounds that have been fired in your SCAR.

[omface@yahoo.com]

I have the die set properly checked again today. After going back and checking the diameter it seems the rounds are buldging slightly at the base by just aboun 3 thousandths. When I reload Hornady or LC brass I don't have the problem, just RP. To answer a question, this is once fired brass shot from my scar and reloaded.

[omface@yahoo.com]

Thanks for the help and input. Has anyone reloaded RP brass on the regular. I shoot/reloaded it all the time in 5.56.

[Raven Armament]

I reload a decent amount of Remington brass. Haven't really had issues that jump out at me. For sizing die, I'm using Redding FL bushing.

[Ttwwaack]

Get a headspace gauge. I've got one and measured some HSM loaded LC brass that grew .009 to .010 on the first firing and the bolt would still close on the case without any resistance. I believe I have my Redding die to bump the shoulder back to SAAMI 0.0 + .007 and it locks up solid. I believe the chamber is in the +.008-.010 neighborhood and plan on neck sizing a case or two for a couple of firings to find its true dimension.

I've only loaded military brass for the SCAR which seems to have a harder case body than commercial brass. If I sized my brass back to factory measurements SAAMI -.003/4 for 3-4 firings the cases would stretch .008-.010 each firing setting them up for early case head seperation.

So far I've only loaded a couple of boxes of Hornady 168 Amaxes and a slew of PPU 145s. I plan on trying some Hornady 150s when I get home and maybe some M80 ball projos when I get back outside this winter.

[T2C]

I ran into this issue reloading for a M1A with tight chamber. I bought a RCBS small base sizing die and that took care of the problem.

Once in a while the case will spring back and needs to be run through the sizing die a second time. A case gauge is handy when troubleshooting this sort of issue.

http://www.brownells.com/reloading/measuring-tools/case-gauges-headspace-tools/wilson-case-gauge-prod33287.aspx

[shootist~]

Without a case gauge (at a minimum) you are really just making a WAG on setting up the sizer die. (Read as "pissing in the wind" - seriously.) Also different brands of brass may require more force to size; not unusual at all.

If using mixed brass, (or even the same brand that's had several loadings), you need to size for the lowest common denominator.

And my educated guess is shoulder setback is the issue - not the base. Properly re-sized brass will still be significantly larger at the base (above the web) than factory fresh brass as noted below:

Example: My unfired Aussie '91 7.62x51 surplus runs .005" smaller above the web than my SCAR fired and 2nd time FL sized and reloaded Aussie brass. .308 factory will be similar with a possibly even larger differential. (My factory Federal .308 measures .002" smaller above the web than my AFF '91.)

My sizing die for the SCAR-17 is a Redding FL (standard base), but I own and use RCBS dies with absolutely no issues. In my case, the Redding sizer is backed out slightly from where I had it set for a Rem 700 .308 bolt gun (using a case gauge as well as the rifle's chamber). It now makes more moderate moderate (vs firm) contact with the ram to allow for the SCAR's more liberal 7.62x51 chamber.

This (fairly minor) re-set was done using a Hornady Cartridge Headspace Gauge kit. The .308 setting was giving me ~.0075" of shoulder setback in the SCAR, which seemed a bit excessive. Shoulder setback will now run anywhere from ~.0035" for older brass to .0060-.0065" for once fired. Those same #2 reloaded 7.62 brass mentioned above run -.005" (vs fired) at the shoulder and ker-plunk into the chamber despite the web measurement. They no longer fall into a .308 chamber, however.

[T2C]

Without a case gauge (at a minimum) you are really just making a WAG on setting up the sizer die. (Read as "pissing in the wind" - seriously.) Also different brands of brass may require more force to size; not unusual at all.

If using mixed brass, (or even the same brand that's had several loadings), you need to size for the lowest common denominator.

And my educated guess is shoulder setback is the issue - not the base. Properly re-sized brass will still be significantly larger at the base (above the web) than factory fresh brass as noted below:

Example: My unfired Aussie '91 7.62x51 surplus runs .005" smaller above the web than my SCAR fired and 2nd time FL sized and reloaded Aussie brass. .308 factory will be similar with a possibly even larger differential. (My factory Federal .308 measures .002" smaller above the web than my AFF '91.)

My sizing die for the SCAR-17 is a Redding FL (standard base), but I own and use RCBS dies with absolutely no issues. In my case, the Redding sizer is backed out slightly from where I had it set for a Rem 700 .308 bolt gun (using a case gauge as well as the rifle's chamber). It now makes more moderate moderate (vs firm) contact with the ram to allow for the SCAR's more liberal 7.62x51 chamber.

This (fairly minor) re-set was done using a Hornady Cartridge Headspace Gauge kit. The .308 setting was giving me ~.0075" of shoulder setback in the SCAR, which seemed a bit excessive. Shoulder setback will now run anywhere from ~.0035" for older brass to .0060-.0065" for once fired. Those same #2 reloaded 7.62 brass mentioned above run -.005" (vs fired) at the shoulder and ker-plunk into the chamber despite the web measurement. They no longer fall into a .308 chamber, however.

When I had issues with reloads not chambering I measured the distance from the base to the datum line on the brass and the measurement was 0.004"-0.006" less than the headspace on the rifles I was shooting. It should have easily chambered based on that measurement.

When I compared the diameter of the resized fired brass at the web, the measurement was greater than the inside diameter of the case gauge. I was use a FL sizing and it was not getting the job done. Once I purchased a small base die, I no longer had feeding issues.

[shootist~]

T2C,

My post was directed solely to the OP. Apologies if it appeared otherwise.

[T2C]

T2C,

My post was directed solely to the OP. Apologies if it appeared otherwise.

No worries. I did not take it personally.

This is a good thread and I appreciate your input.