260 is Numerical Code for Picky! She says no to Amax's.

[Wildwillalaska]

As I was trying to work up a load with my new-to-me 260 Hospitaller, I went mainstream and started with H4350 and 140 Amax's. Did a ladder at 500 looking for node between 41.5 and 43.3 grains. I also loaded a couple dozen with 42.5 grains to foul the barrel, zero, and simply play. I, and the rifle, we're unimpressed with 100yd accuracy.



So today tried a couple spots that looked to have some potential from the cluster of a ladder and while at it tried some Berger 140's too. Conclusion, gun hates Amax's, but shows promise with the Berger Hybrids.

Two different loadings with Amax's.



Here are 42.7 and 42.9 grains of H4350 with the Berger Hybrids. Same charge with Amax's are at bottom right of center as I was using the bottom right corners as additional aiming point.


Really surprised by the dramatic difference between the two bullets.

Still more work to do, but it will be with the Bergers from here on in this gun. Love Amax's and use them a lot for my 308 and 300, but looks like the 140's will have to wait for my creedmoor as the 260 stick says NO!

 

[gafferq2xl]

Same problem with H4350 and AMax but I was totally set on using the AMax. Too bad because I had 16 lbs of it!! Don't give up on them. Mag Pro could be an option but in the end for my gun H4831SC did the trick. 46.0gr and it was good to go. I didn't do the development thank God because 5 different powders were used to get it right and I didn't have access to anything near that.

 

[BoilerUP]

Probably a stupid question, but did you try just one OAL with the A-Max?

 

[427Cobra]

Adjust your seating depth

 

[groundhogbuster]

I bet the groups will shrink if you stuff 47g of H4831sc behind that 140. My Beanland build was the same way, and when H4831sc pushed the pill, the groups are in the .2's" . I have 2 260's Beanland & Spencer, and they are super easy to tune. Jon is using a different reamer with a shorter freebore and it's smokin accurate.

 

[Wildwillalaska]

Last week, the fun rounds were split between .010 and .005 jump.

Figured it might want more, today was .017" jump with the Amax's,

The Bergers was seated deeper to mag length with .022 jump.

I'll try some 4831SC--just picked up a new keg of it last week.

So will tinker a little more with the Bergers and H4350 and try some if the H4831sc and Amax's. Not holding my breath though. I have a Creed coming so plan will be to use the Amax's in it if things don't tighten up. Always nice to just settle onto one boolit if possible though.

Do folks think more jump with the Amax or try jam with the 4831?

 

[gafferq2xl]

I modify jump in .005 stages out to +.030. Kissing to -.010 shouldn't be overlooked though. Just be sure your load is reduced as this will increase pressure.

 

[918v]

Bullet seating depth aside, there could be another thing you could try: I don't load for the 260, but in the 308 I found that it prefers brass with the least case capacity. The same velocity/ES in a Winchester case shot twice as large as in a LC case. Perhaps you could try to rework the load in different brass? I dunno how much variance there is between the different .260 brass brands, but it might be worth a try.

 

[Wildwillalaska]

Some guys love shooting jammed for whatever reason--at the same time I have a preference against it. I have only one rifle--a hunting rig--that I shoot jammed. All my guns I have loaded for I always seem to find an excellent load with a jump between .005 and .0025. But pretty plain jane in my bullet selection.

Shooting Lapua brass.

The Bergers show real promise, so figure I will find a good load in there--was just very surprised in the difference between the Bergers and Amax's down range.

 

[BLDTYLRY]

+1 on seating depth.

Finalized my load this weekend and .010" off the lands with 140gr a-max. Where as in my 338LM, .040" off the lands was preferred.