What Difference do Primers Make? 210M vs WLR

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PathFinder1776

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I'm in the process of working up a load for a new rifle (6.5 CM), and the best I've been able to get it to shoot is 3/4 MOA. I've used four different powders (H4350, RL17, Hybrid 100V, Varget) and two different bullets (140 Barnes Match Burner, 140 ELD Match), but only WLR primers. Factory Hornady 140 ELD Match (43.x g 100V, 210M primer) shoot closer to .6MOA at 100 yards, and hold just barely sub MOA at 700. Could the primers be the difference that I'm missing? I still have two powders to try tomorrow with the ELD Match (RL 17 & H4350) but so far I've been able to get every combo to shoot .75-1 MOA, but no better. Any experience comparing WLR primers to the 210M?
 
No, that's a little to fine for me, being in the hunter department. One would have to keep all the other variables constant, while checking if there was a benefit. There may be, slightly.

I've read a few articles in Handloader Magazine where they go out to prove or dispell reloading myths. There can be a fine line between something that actually helps or if the loader 'thinks' it improves accuracy.

I do use a standard or mag primer, depending on circumstances and what the load calls for. No matter what we do, the next may experience different results.
 
Guys over at 6br.com would be the -place to go. Lots of knowledge & experience on technicalities. My favorite site. Uh next to this one.:)
 
They can make a difference for sure all depends on what you are after benchrest guns , in a class all their own.
Hunting guns sometimes will drive you nuts looking for the mighty grail of loads but it's there sometimes it's a lot of determination and a little luck lol.
I shoot cci br primers in all my guns except one 223 that likes the magnums primer .
So it's all in what the gun wants,

You can also check out benchrestcentral
 
Originally Posted By: scoremasterThey can make a difference for sure all depends on what you are after benchrest guns , in a class all their own.


In my .17 Remington, my .204 Ruger, my .221 Fireball, my .223 and my .223 AI have all shot their best groups with CCI BR primers. I do not think that was coincidence. Alas, the BR caps have gotten so expensive that I rarely buy them now (and I used to bitc# when they were $20 a brick!) and just use whatever SR primers than I grab. If I miss a 400 yard prairie dog then so be it. I'm not going to know if it was because of my primer or not. I just dont worry about it.
 
Most of my handloads would crater a standard primer. I use Rem. primers in both small rifle and large because of the harder cup surface. Benchrest and magnum primers have a harder surface and will stand more pressure.

James Calhoun has a very informative article on primers and pressure on his website.
http://www.jamescalhoon.com/
 
Primers make a whale of a difference, and this statement has to be kept in context that you are wanting to develop loads that shoot .500" and below.

Fed 210's have a very soft flame, win has massive flame and incandescent particles that shoot through the entire powder column. Trial and error is what helps determine what works.

A friend took pictures of primers going off and his pictures were published in Precision Shooting magazine in the early 80's, and it is amazing to say the least.

I load right at the rifle range, making changes immediately upon trial and error. I tweek the powder charge, seating depth, then primer, it is very often a "Oh WOW" moment when you change primers both good and bad.

For a guy that is looking for 3/4"-1" groups which is more than adequate for all hunting, changing primers may have little consequences. Over sizer firing pin holes in bolt faces demand the use a thick cup primer:
Rem 7 1/2
CCI BR-4
CCI 450
CCI 41

Match burner, you should play with jumping that Barnes bullet, in and out if you have latitude in your magazine. Also, we had great luck with the 129g Barnes long range this year, tuned easily in .350 groups and much smaller. If you have played with the OAL, then it is time to change bullets. H4350, IMR 4350, and AA4350 all shot great for us. It really sounds like you are trying to get a bullet to shoot that your rifle just does not like. 140g Berger hybrid tuned easily also, seemed like the accuracy node is around 2750 for the 140's.
 
Awesome thanks for the info fellas. I definitely have an oversized firing pin hole, even low and factory loads leave a crater. I am going to try jumping the MBs tomorrow, and try some Rem primers.
 
Send your bolt to Gre-Tan rifles and have the firing pin bushed, Greg Tannel does a fantastic job. Large rifle primers are LOT harder to pierce than small rifle primers due to cup thickness.

I have shot 257 Weatherby mags for years, everyone of them crater primers at the top end accuracy node, I just ignore the cratered primers in LR. Now pressure indicators like increased bolt lift or case head marring are indicators to back off on you load right now.
 
Found a killer .5MOA load with 130 HVLDs, CCI 200s, and H4350. The rifle really loves this bullet. It will open up to 1 MOA as it gets away from a node, and settle in and shoot well under MOA, down to .5 MOA through the middle of it. I had primer cratering all the way through from minimum to my current load (42.7) which is two grains under max for the rifle. Really might have to have the pin bushed, I can't believe they left it so large on a high end rifle.
 
Never noticed much of a difference between 210 and Win primers in my loads. Have used both and unless you are shooting 1/4" groups consistently, you probably won't notice any difference between them. I prefer Win. I have shot ccibr4's that seemed to show a bit more accuracy but can't find them anywhere.
 
That scale (Nice find!) just goes to show once again that anytime we change anything on a load we need to back up and develop the load again. Not only can/do pressures change, but accuracy can change also.
 
I miss Precision Shooting magazine. Sent my money in for a year subscription. About 2 weeks later heard they went out of business. Great articles - some way over my head. Still miss it though.
 
Primers do respond differently.When changing a primer its burn rate and tempature effects the speed of the burn rate of the powder. This will change the pressure arc in the brass.bullet seating depth also makes a big change on the powder burn rate. If your having problems getting sub moa groups.I would recommend checking your head space as well.look at your burn rate for your powder and your pressure on your reloading charts.try and get a even push instead of a sharp snap in your pressure curve ,and go for 93 to 98% case compasity. Below that you usually get wide velocity strings.
 


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