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  • Need some advice on a .308 reloading issue

    Posted by james on June 23, 2022 at 11:22 pm

    Hello all!

    I’m pretty new to reloading .308 (maybe like a few months into it) and I am encountering a strange issue with cartridges not chambering in a bolt action rifle (Remington 700). They’ll chamber in my M1A with no issue, and of course they seem perfectly in spec according to my case checker and calipers. I have fired them in my M1A previously, and I don’t think that they formed to my chamber simply due to the fact that all other dimensions along the case/neck are correct.

    Any recommendations on what I can look for?

    james replied 1 week, 2 days ago 2 Members · 7 Replies
  • 7 Replies
  • papamcb

    June 23, 2022 at 11:22 pm

    I would load for each rifle separately. This will be more work but you will have a more accurate round for each rifle.

    Or the other option is load for the smaller chamber, this is what I do with 223

  • 101stjetmech

    June 23, 2022 at 11:22 pm

    When you full-length resize, make sure the shell holder contacts the die when actually sizing.

    M1A, M1 will both chamber rounds that have the shoulder too far forward just because of the chambering force of the spring. We saw this at the CMP games a few years back. Issue HXP that worked just fine in the M1s would not chamber in most of the 1903/A3s. Someone had a case checker and we found that batch of cartridges had the shoulder too far forward – beyond SAAMI specs.

  • 01069

    June 23, 2022 at 11:22 pm

    How are you measuring them? With a shoulder gage? What sizing die are you using? Is it a small base?
    Assuming oal case length is within spec.

    Easy way to find out is 1 case bump shoulder back 2thou increments. Keep checking to see if bolt closes. If you bump it a good amount and have the same issue then switch to a small base die.

  • CptAmerica007

    June 23, 2022 at 11:22 pm

    I had the same issue. My reloads had no issues with some of my rifles, but they would not correctly chamber in my Savage bolt action. The solution I discovered was to convert to a small base resizing die. No issues since then.

  • ocelot_piss

    June 23, 2022 at 11:22 pm

    Figure out which part of the case is the culprit preventing it from chambering. You can mark it with a sharpie. It’s likely the shoulder not being bumped enough or the case head having expanded too much.

    Case checkers are of limited use. They mimic a round going into “a chamber” but that’s evidently not the same as your rifle’s chamber.

    Best to segregate your brass for each rifle, unless you know the chamber dimensions match.

  • Which_Quantity

    June 23, 2022 at 11:22 pm

    Full length resize every time? Otherwise you probably have to make separate loads for each rifle if you want fire-formed brass.

  • therealvulrath

    June 23, 2022 at 11:22 pm

    I’m going to make an assumption that you’re full length sizing. You shouldn’t neck size, that’s Fudd lore and at best will get you some lost accuracy. At worst the case will get stuck and you’ll end up breaking the handle off your bolt trying to get it open. Consistency is the name of the game here, and neck sizing isn’t consistent.

    Is your case checker a comparator or is it one of those drop-in gauges? If the former, then you don’t need to buy anything or do anything special for what I’m going to suggest for the actual issue. If the latter, you really need to get a comparator. You can get by with a properly sized (or just new) 9mm case flipped over and placed on the shoulder. Just measure from the case head of the 9mm all the way to the case head of the 308 case.

    Now, you should take some factory ammo and mark it, then shoot it in the 700. Take that case and measure it with the comparator, then see what the difference in length is between your chambers. Alternatively, you could just bring the die down a little bit at a time and then try it in the gun until it chambers. That’s what I did to set my dies when I first started (my, how far I’ve come).

    Is the 700 barrel factory or does it have a custom barrel? Factory 700 chambers are usually a little more generous than custom chambers from a gunsmith, but it would make sense (at least to me) that the M1A is going to have an even more generous chamber.

    I would highly recommend papamcb’s suggestion and separate your brass by rifle. That’ll allow you to ditch SAAMI specs for sizing and size to your ~0.002-.003 under fired for each rifle to allow for the best performance of each rifle.

    If you’re not already, I’d also recommend you join the Reloading Discord. The 308 channel is a wealth of information and there’s enough folks to get an informed response pretty quickly most of the time.

    EDIT: I forgot a couple of words in relation to SAAMI specs. The specs listed on the spec sheet for a cartridge are intended for manufacturers, so that they can produce ammunition for any firearm at the cost of some potential accuracy. They don’t care about brass life because as far as they’re concerned it’s only ever used once and then discarded. Think about it as a minimum, and the fired case as your maximum.

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