Bullet jump vs mag coal.

[whoami-72]

Sorry guys, I'm attempting to get back into reloading after a 5-6 year break and have some dumb questions. I had mixed results back then but never really got seriously into it.

Situation:
I'm reloading 6.5 creed and .308 win. When determining seating depth I was going to try and find jam on my rifles then back off .02" as a starting point. I don't have comparator tools so everything is measured in COAL. To find jam I used the lock tite method and barely seated a bullet put it in the rifle chambered and waited 10 minutes. I did feel like I had to force the bolt closed on both which I was expecting however I had to try a few times on the 6.5 CM

Problem:
After finding jam, I realized I was .05-.06" above my magazine length. This made me wonder if I completely messed something up because everyone on YouTube mentioned to back off .02" but I can't do that and fit in my mag. Am I crazy? Is this normal? I ended up just loading to the max mag length -~5 thousandths.

Equipment:
Not sure it really matters but I thought I'd let you guys know anyway. Rifles are matching seekins PH2's. .308 rifle has ~500rds. 6.5 cm has ~150 rds on it. Brass is norma once fired in both. Bullets are 140gr sst in 6.5 cm and 150gr sst in .308. I plan on switching to copper but had leftover sst's to practice with.

 

[streamerfish]

It often depends on the barrel and the bullet being used.

But its pretty normal for your oal to be determined by your mag length.

 

[hoooogan]

What magazine do those have?

Standard AICS 308/6.5CM usually has a ~2.85" COAL max. A handful of my 6.5CM bullets get jammed at 2.89-2.91" COAL, with a couple others in the 2.96-2.97" range. So the min jump I'm getting is 0.040-0.060 on some with others being 0.110+" when I'm using that magazine.

My Springfield 2020 action allows the use of a non-binder plate steel AICS mag which opens up to 2.950, so it's possible to load everything from jam to 0.020". But not every action is clearanced for that.

All this to say, if you are truly restricted by your magazine length, work from there otherwise you will need to single feed everything if you want to be closer. Being close to the lands is not a requirement for accuracy. You need to be where your rifle likes it.

 

[JFK]

Were the cases you used to do the locktite method sized? The amount of force required to seat a bullet if the necks were resized would have you into the lands. Not just kissing them but a very hard jam of maybe .015 or so. If you are going to reload and try to tinker I’d get a Hornady oal tool, or just load to mag length. I’ve only recently got the Hornady tool and loaded very accurate ammo for years by just loading to book length. Messing with seating depth is way down on my list of things to do if a load doesn’t shoot.

 

[Steve300xcw]

Mag determines the OAL more times than not for me.

 

[whoami-72]

What magazine do those have?

Standard AICS 308/6.5CM usually has a ~2.85" COAL max. A handful of my 6.5CM bullets get jammed at 2.89-2.91" COAL, with a couple others in the 2.96-2.97" range. So the min jump I'm getting is 0.040-0.060 on some with others being 0.110+" when I'm using that magazine.

My Springfield 2020 action allows the use of a non-binder plate steel AICS mag which opens up to 2.950, so it's possible to load everything from jam to 0.020". But not every action is clearanced for that.

All this to say, if you are truly restricted by your magazine length, work from there otherwise you will need to single feed everything if you want to be closer. Being close to the lands is not a requirement for accuracy. You need to be where your rifle likes it.

They take AICS mags. I have a handful of p mags, mdt, and ammend 2 mags that I cycle through. I never actually measured the mags. I was just going off of "book spec" for mag length. Interesting point on some being bigger than others.

 

[whoami-72]

Were the cases you used to do the locktite method sized? The amount of force required to seat a bullet if the necks were resized would have you into the lands. Not just kissing them but a very hard jam of maybe .015 or so. If you are going to reload and try to tinker I’d get a Hornady oal tool, or just load to mag length. I’ve only recently got the Hornady tool and loaded very accurate ammo for years by just loading to book length. Messing with seating depth is way down on my list of things to do if a load doesn’t shoot.

Bingo! this may have been the issue. I have Hornady custom dies. So in order to pop the primer out I also sized them. I wasn't able to slide a bullet in by hand and had to push really hard to "seat" the bullets. However, I just grabbed a once fired case and the bullets were able to slide in just fine. I have a feeling you just nailed my issue. I'm going to try again with a deprimed but unsized case now.

 

[il_cop]

For me, I start with the boat tail/bearing junction seated at the neck/shoulder junction. If that doesn't fit the mag, I'll seat deeper until it does. If the mag is generous,I've never gone longer. Never had the need. If it doesn't shoot, I'll change powders...if it still doesn't shoot, I'll change bullets and do the whole thing again.