260 Rem max load data

I just started loading for my new 260 Rem. The best load I found in my 20" 1:9 twist using 120 grain sierra mk hpbt with 44.5 grains of H4350 getting .50 at 100 yards.

My chrony says im getting 2935 average but my load data Lee reloading manual says max is 46.5 compression load and 2915 fps with this load. So why am I getting 2935 out of less powder and shorter barrel?

I thought chrony was wrong so i zero at 100 then took it out to 300 and found my drop 12" at 300 is consistent with my fps. Has anyone found such a discrepancy in the load data?

My primers aren't flat and no case deforming or extractor marks showing high head pressure and this is not a compression load seating the 120's at sammi 2.80.

I just found it odd but this is the best group I get with the powder bullet combo.

I love it when that happens. You might have a tighter chamber and some barrels are just faster than others. Brass type and quality can also make a difference. If your not seeing any pressure signs or reasons to change anything I wouldn't. Sounds like you got a sweet running rig to me.

So far so good, I am just breaking in the barrel but the groups are promising. This is my 300 yard target, didn't really have a constant point of aim just center of target. The 260 is one of the sweetest shooting rifles I've shot...


http://i1109.photobucket.com/albums/...psea1270a1.jpg

Yep the 260 is one of my favorites. What did that group measure? Looks like its holding at least moa at that range.

Glad to see you on the forums and see that barrel doing OK for you! :cool:

Might wanna try some RL-17. I'll bet you get even more velocity and may shoot even better.

I second that RL17 easy 100+ fps more

Nice shooting on that orange fellow there!!!

Few things about this situation and the powder.
With about a 3 grain spread min to max, that is an indicator that the powder isn't all that suited to that case. 4350 was designed around the 30-06. And has been changed somewhat in relatively, recent years. When things are different, they are different. The SMK's will have less surface on the bore, than the Speer bullet that the testing was done with, so that will also be a contributor.

Thanks guys...the barrel is great..too much fun...i will try some R17....if i can keep that group with less head presure the better....the group is just under moa if i use approx center hits...i didnt have a point of aim i just guessed. 10x leupy i couldnt see my hits so it was a.challenge...oh my barrel is from apache...good stuff

I use H4350 in my .260 but it's a 30in. barrel. At 20in I would suggest a faster powder like H-4895 or Ramshot TAC.

Varget works good in that case too. Reloader 17 if you can get it to shoot good would be the way to go.

I worked with Varget and H4350 and found H4350 easier to work with for the 260. Plus Varget doesnt get me the velocity I am looking for.

I just worked out a load for the 120 SMK using 45gr H4350 and drop data shows it is at 3150 fps. I got better than 1/2moa at 700 yds with it.

I got my Remington Model Seven to push 129 SSTs at 2897 out of my 20" 1:9 twist barrel with 49.3 grains of RL22. Might work even better than the 17. 17 is allegedly stupid temp sensitive.

I have two 260 rifles based of savages. Both are 1/8 twist barrels. The first is a shillen at 26" and second is Criteron at 24". I am currently shooting most 140 grn pills at an average 2850 fps which is a fair amount faster than all three books say it should be for the given powder and load. That happens all the time. Start at the mid range load in books and work up to hit accuracy node. Also remember that seating depth varies from books with most rifles. My loaded rounds are a lot longer than the sami specs on every load for every bolt rifle. That will be true of most savage short actions as they have long mag areas to allow for bullets to be seated into lans if you want to. Both my barrels are match, long chamber ( not loose, but long) to allow for 140 grn pills to hit lans. The whole thing gets different when you are not loading to exactly the same oal as the book lists. Therin lies the gray area as you would think less bullet protrusion into the case neck would lower velocities but I have not found that to be the case.
for example most books loat the 260 to an overall length of 2.8". Well most of my loads run around 2.87 oal. The nosler book lists the 140 loads with the powder that I use and same charge at more around 2750 - yet I have a lot longer oal and still reach 100-150 fps more with no pressure signs. Books are just a vague starting point, not gospel - heck they are not even likely to be close, just safe. Note what type of chamber is used to test in book ( loose factory or custom, tight. Also some pressure signs are really due to sloppy chamber compared to sizing of brass - if you do not get good brass to chamber fit the primers can show signs when there really is not high pressure.

Same for me as Kimbajmann. I just ran mine over the Crony today. Match prepped Lapua brass, BR2 primer, 43.5g of H4350 Hornady 140 Amax seated to 2.90 which is just kissing the lands on my Lothar Walther 24" 1:8t barrel. 2850 with an ES of 13. No pressure signs.

For kicks I made up 10 rounds with LC .308 cases. Just ran them through the FL Redding and seated the bullet with the same load. The bolt would not open. Had to bang it open! Flat and cratered primer with ejector swipe so way over pressure. Obviously the neck was way to thick so I'll have to turn them and back off the load and work up. I'll be pulling the rest! Funny cause the rounds I make with 7-08 and .243 brass work great with just sizing and trimming.

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Originally Posted by Rifleshooter308

Same for me as Kimbajmann. I just ran mine over the Crony today. Match prepped Lapua brass, BR2 primer, 43.5g of H4350 Hornady 140 Amax seated to 2.90 which is just kissing the lands on my Lothar Walther 24" 1:8t barrel. 2850 with an ES of 13. No pressure signs.

For kicks I made up 10 rounds with LC .308 cases. Just ran them through the FL Redding and seated the bullet with the same load. The bolt would not open. Had to bang it open! Flat and cratered primer with ejector swipe so way over pressure. Obviously the neck was way to thick so I'll have to turn them and back off the load and work up. I'll be pulling the rest! Funny cause the rounds I make with 7-08 and .243 brass work great with just sizing and trimming.

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yep I necked down some lapua 308 to 260 and had to turn the necks as well - am using them on the criterion barreled 260 just fine. I use vitt 550, rl19, imr4350 in the 140 and use a variety in the lower weights ( rl 17 superperformance, varget)

Nice shooting, just got my 260 ai together and looking to get it out running. with the rl 17 have you guys noticed temp sensitivity or how much?

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Originally Posted by calib

Nice shooting, just got my 260 ai together and looking to get it out running. with the rl 17 have you guys noticed temp sensitivity or how much?

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I am loving my two 260 rifles and look to build a 6.5-06 next. am trying to trade two scott fly rods for a savage long action -06 bolt head to buyt a barrel for. 6.5 seems to be perfect for my needs

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Originally Posted by calib

Nice shooting, just got my 260 ai together and looking to get it out running. with the rl 17 have you guys noticed temp sensitivity or how much?

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I think the temp sensitivity thing is not of real concern unless you really wringing out the vel and range. At 400 or under not a real issue with the flat shooting 6.5

if you are pushing the way extremes it might, might be a real issue.

sorry, no long action here.

My 24" Criterion 260 Rem match chamber is getting 2800 avg with H4831SC and 140 Hybrids loaded .015". 12 shots over the chrony gave 11 ES. H4831 works really well and its a full case in Lapua brass.