Primers Once Again....?

[Powerstroke]

Ok, I'm off to the range for the last time before season starts. I'm confident with the .300RUM.
Question being, cases that reach a capacity that you are compacting the powder when seating the bullet.....how critical is primer choice?
This is my wifes .260 that I've always used CCI-BR's The same primer that wasn't getting the job done in my .300. If switching to a Mag primer, am I correct in reducing the load 10% ??

 

[JD338]

YES! ALWAYS work up loads when changing components. The Mag primer may give you higher pressures.

JD338

 

[rick smith]

Don't think you need a mag primer in a 260 sized case but if you want to try one reduce the load first. Rick.

 

[7 STW]

Too much primer for a 08 size case.If you want more heat try the Winchester WLRP it's the hottest standard primer out there.If you use a mag primer work her up from the begining.

Honestly I would never even think magnum primer in such a small case.

 

[300rummy]

When changing to mag primers you only need to back of a half of a grain or a whole at max, they don't have enough variance to back off nowhere 10%......backing off that much would completly change the whole load, say you were loading 49 grains in the load , 10% would have you knocking back right at 5 grains, changing the load dramaticaly when your just wanting to change primers...

 

[300rummy]

As far as mag primers go, I use them in ALL my hunting loads, even in my sons .243, every load book I have with people such as Layne Simpson recommend to always use a mag primer for hunting loads in these size cases as well as the big dogs......they just advise to back off a half grain to compensate the difference.

 

[300rummy]

Too much primer for a 08 size case.If you want more heat try the Winchester WLRP it's the hottest standard primer out there.If you use a mag primer work her up from the begining.

Honestly I would never even think magnum primer in such a small case.

Just curious as to why not?

 

[Guest]

I use mag primers in many of my cases, including some in the .308 family, like my .243Win. The main reason I use mag primers is for better ignition of fairly load-dense charges of ball powder of various types. Reading load manuals, you will find that nearly everything in a 30-30WCF load data table carries a mag primer, and the manufacturers recommend them pretty much across the board for this cartridge. I get excellent results.

 

[Ol` Joe]

I believe the bench crowd condidered the mildest primer that reliably ignited the powder charge to usually give the best accuracy. If you check all BR primers are of std type and not mag except I think for the Remington 7 1/2 small rifle which i`ve seen in both BR and mag designation.
I use the Remington 9 1/2 LR in my 260s (2 of them) with good result. The WLR is my 2nd choice with some powders/bullet wgts but R22, R19 and H4831sc all work very well in the 260 with the std Remington. (All are compressed, or very close to it, at max with 129 -140 gr bullets) I used the WLR with H1000 in the same cartridge but likely would get just as good result from the Remington.
The only place I have seen mag primers recommended for 30-06 sized case and smaller is in the Speer load manual. Then it is only with ball powder. They also use std primers in a lot of magnum cartridges with faster powders. Winchester which only produces ball powders also uses std WLR primers in their data for smaller cases instead of magnum. A rule of thumb I have heard others go by is std primers for powder charges of 60 gr or under and magnum primers for heavier ones. The mag primers might also be of advantage at very low temps with ball or very slow powders. I don`t know how much effect they will have in either case but I have regularly used std primers down to 5-10* F with slow powders and found no ignition problems here in Michigans winters. Any colder and I stay off the range and by the fire.
If you have a croney you might try a couple different brands and types of primers and see if the extreem spread or accuracy of your load improves with one over the others, and stay with that one. You also are correct in reducing your charge and working back up. I personally would likely only go back 5% or a couple grs and compare the result to what the old load at that point did. if there is no large increase in velocity and primers, case expansion, ect seem similar I`d go up to my max load in 1.5 gr or so increments instead of .5 or 1.0 gr.

 

[Powerstroke]

Awesome Info guys, I appreciate it.......also have to apologize for not giving the complete story.
This .260 is a Model 7 ie..very short barrel. I tried some RL-19 / 100grn B-tips and CCI-BR2's today. Actually the best results I've had with this gun @ 1.00in. The other, which was brought up, was temps. I was hoping to play with this round a little this winter hunting yote-s. Ten to twenty / thirty below wouldn't be unheard of.

Old Remington 7mag shot .375in groups all day today with a new load.
63.8 Grns RL-19 & 140grn A.B.'s Federal 215's of course.

Thanks for the info !!

 

[kosh]

Awesome Info guys, I appreciate it.......also have to apologize for not giving the complete story.
This .260 is a Model 7 ie..very short barrel. I tried some RL-19 / 100grn B-tips and CCI-BR2's today. Actually the best results I've had with this gun @ 1.00in. The other, which was brought up, was temps. I was hoping to play with this round a little this winter hunting yote-s. Ten to twenty / thirty below wouldn't be unheard of.

Old Remington 7mag shot .375in groups all day today with a new load.
63.8 Grns RL-19 & 140grn A.B.'s Federal 215's of course.

Thanks for the info !!

I have a 260 22" barrel RL 19 seems to be just a tad slow for 100's then again it could be the lot # of the powder I have. H-414 on the other hand is just the ticket in this rifle. Do you have a 20" barrel or 18.5" ? I can't remember if the .260 was produced with the 18.5" before the 20" became the standard for the mod 7 . You might aslo want to look at 4064 or RL 15 as they are listed in the manual but I have not tried them yet. The 260 is an excellent cartridge.

 

[Powerstroke]

kosh,
It's the shorter of the two, I was almost thinking 18in. I tried some of the 4064 which was not bad. I need to figure out what I am going to use this rifle for.....it's actually my wifes and has done a number on a few elk.
I am also curretly having a 700 rem varmiter ( originally a 22-250 ) turned into a .260. Should be done next week.

 

[kosh]

Powerstroke


What twist are you getting the new 260 in? Mine has a 9 twist which seems to be the norm for our domestic Mfg's. I would prefer an 8 twist so I could shoot 140 grain bullets. A BT at a weight of 140 grains should have some serious ballistic coefficent and properly coaxed with load of either H-4831 or Rl22 would make for a real long accurate hitter for yotes and such. Would make a very good deer bullet for big deer. Hmmm 140 BT ( nudge nudge wink wink)


Have you tried the 120 BT or the 125 Partition? I am having excellent success with the 125 Partition . Two shots at big game and two bang flops last one 2 weeks ago was at a ranged 327 yards . When I decided on the 260 it was for a light carry rifle for high country. Well it is sweet in the low country too. Tomorrow I am heading out for Elk and mule deer and with Elk my first priority the 260 is getting some time off and my 06 is the rifle of choice. I would not feel lost with the 260 if I had a shot at a good bull but it would have to be 200 yards or less and in the lungs. The 06 gives me another 100 yards with a 180 AB and a good charge of RL22.


If I knew how to post a picture I would show you what the 260 is capable of on biger critters with that 125 Partition at 100 yards.

 

[Grove]

A couple of things I learned neerly 30 years ago about primer selection for a given case has more to do with the powder type and the outside air temperature you will be hunting/shooting in.

Let me clarify. For most non-magnum size cases, using relatively quick powders such as 4895, 3031, 4064, 4320 ... a standard primer will be adequate for good ignition and accuracy. If you are using slower powders or ball/spherical type powders, such as 4350, 4831, H414, W760 you will need a hotter or magnum type primer. The ball or spherical powders can be harder to ignite reliably because of the coating that is used in the manufacturing process.

Now, the one factor that most people don't consider is the out side air temperature. Best rule of thumb, if you are hunting when the temperature is at 0 degrees or lower ... use a magnum primer. The powder in the cartridge will be harder to ignite when it is really cold. Especially, with the slower or ball type powders. I lived in South Dakota for 11 years and hunted when it was 20-30 degrees below zero. I saw a lot of hunters that had bad hang fires or misfires because they didn't use the right primer for the climate.

Just adding my 2 cents. Hope it helps.