Mods, if this is in the wrong section please move it to the appropriate one. Anyway on to my question. I have read a lot of posts, both here and throughout the interwebs about the two different sized primers for 6.5CM. it has become rather confusing trying to keep it all straight in my mind. I understand that if I want to use the small primer that the firing pin needs to be bushed, does it need a different firing pin also? I have a Howa 1500 6.5CM, I am thinking I should contact LSI and ask if their standard setup is already setup so it can use the small primers. Does anyone else’s rifle come standard setup like this or is it something that always needs done? Any help or information would be greatly appreciated.
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Small primer for 6.5CM
- Thread starter Macman25
- Start date
A Vanguard IS exactly a Howa 1500. The minor external cosmetic differences are inconsequential.
Don’t necessarily need to bush the firing pin for 6.5CM.
Some brass, like Lapua, only come in small rifle primer in 6.5CM.
I wouldn’t go to the trouble if you aren’t having any problems.
In fact, I had more problems with soft large primers and not with small primers.
Some brass, like Lapua, only come in small rifle primer in 6.5CM.
I wouldn’t go to the trouble if you aren’t having any problems.
In fact, I had more problems with soft large primers and not with small primers.
I had pressure problems like crazy running factory Lapua ammo. Problems bad enough to never want to run small rifle primer ammo anymore, unless I get the pin hole bushed. Otherwise, there is no way i will use SRP anytime through my rifle. My rifle is a howa 1500 in 6.5CM.
I just picked up an RPR in 6.5CM. Looking for brass as we speak. I was leaning toward SRPs because I have more in inventory. Any issues with RPR and SRPs?
My bergara hated SRP. Bergara didn't think it was an issue since 6.5creed is suppose to be LRP, according to them. Needless to say but I dropped that platform and will never buy another Bergara product.
I am getting pierced primers in my RPR using Lapua SRP brass loaded with 1.3 grains less powder than what I use in Hornady brass.
I have an older Bergara with a premier action, which has a larger firing pin. Newer actions are supposed to have a smaller pin.
I do see cratering in small rifle primer brass as I get higher into the pressure range. With new brass where the case is expanding quite a bit to fill the chamber you can see that it’s starting to extrude a “plug” into the firing pin hole. Thankfully I’ve not had one actually punch the plug out.
I’ve also had problems using milder primers. I have a pretty good stash of older Wolf SRM primers, which was my motivation for getting small primer brass. They have a great reputation for consistency, and that’s borne out for me in .223 loads. However they do not reliably ignite the powder in my 6.5 Creedmoor loads. I had issues with multiple duds, and consistent hang fires. I switched to CCI 450’s and have not seen any issues since. Could be specific to that lot-era-brand of primers, but it’s something to be aware of before you buy
a ton of a specific brand of primers.
I do see cratering in small rifle primer brass as I get higher into the pressure range. With new brass where the case is expanding quite a bit to fill the chamber you can see that it’s starting to extrude a “plug” into the firing pin hole. Thankfully I’ve not had one actually punch the plug out.
I’ve also had problems using milder primers. I have a pretty good stash of older Wolf SRM primers, which was my motivation for getting small primer brass. They have a great reputation for consistency, and that’s borne out for me in .223 loads. However they do not reliably ignite the powder in my 6.5 Creedmoor loads. I had issues with multiple duds, and consistent hang fires. I switched to CCI 450’s and have not seen any issues since. Could be specific to that lot-era-brand of primers, but it’s something to be aware of before you buy
a ton of a specific brand of primers.
I’m guessing the pressure problems with small rifle primers in Lapua brass are due to the small rifle primer flash holes and that’s why Starline makes their SRP 6.5 brass with a large primer flash hole for better flame propagation. I know, its not the same quality as Lapua brass, but it would be interesting to see how the different flash holes performed differently pressure wise with all else the same.
Really bad over pressure signs. Sticky bolt, cratered primers, even primers falling out when I ejected the spent case, and really shitty accuracy.
No, I am not saying the ammo was not good. The ammo was factory Berger so it doesn't get any better. I just simply can't use SRP in my rifle unless I bush the pinhole.
I am not getting any pressure signs, other than cratered primers. I get around 3 out of 10 pierced primers.
Accuracy is great, for the virgin brass, get hits out to 850 yards and 14 SD for 20 round string.
Accuracy is great, for the virgin brass, get hits out to 850 yards and 14 SD for 20 round string.
That sounds like there's some other stuff going on, not caused by small primers.
I'll hear you out if you got anything in mind. I'd like to take care of it at one point.
I don't know particulars of your barrel/chamber, but srp won't cause pressure signs like loose primers/primers blowing out or heavy bolt lift. What you will see in srp and large firing pin is cratered primers or blanked primers. As mentioned by a previous poster, your signs yell chamber pressure to me. Now whether thats from short freebore, short headspace, wet chamber, or just too hot ammo got me. I'd need to measure chamber to see where issue is. What is the velocity of the rds that are exhibiting these behaviors?
Large firing pins aren't necessarily bad with small primers, as long as they fit the aperture in bolt face closely. I think the srp brass handles pressure better than the lrp brass. I also like the smaller flash hole, as it contains pressure in case and shows less pressure on primer.
Large firing pins aren't necessarily bad with small primers, as long as they fit the aperture in bolt face closely. I think the srp brass handles pressure better than the lrp brass. I also like the smaller flash hole, as it contains pressure in case and shows less pressure on primer.
I don't have any problems with the Lapua srp brass and rem 7 1/2s in a 1st generation Ruger RPR. It is a 142smk and h4350 load at book max, 7sd as reported by the 1000 yard electronic target for 20 round relay.
I have a Howa 308 Win that I rebarelled into a 6.5creedmoor. I also thought about getting the pin bushed since I’m using small rifle primers. Decided to give it a try first and I’m glad I did because it ran with zero issues.
Lfp aren't the devil, with small primers. Loose fitting fp to fp aperture is a main issue. If you have a .080 fp and a .086-88" aperture, no issues. The problem is on some rem and other factory actions, the aperture is .095+". That results in cratered primers and sometimes blank primers. My ae mk3 would cratered primers badly with a 6.5creed barrel, had lri bush the bolt and craters went away and could go up to next accuracy node, about 40fps more. My ae mk2 had a better fitting fp and aperture, I could run small primer 6.5creed brass hard and never see any primer catering. The main difference, again, was how the fp fit the aperture.
First two are SRP Lapua brass loaded with 41.4 grain of RL16 under 140 ELDM's and Rem. 7 1/2 primers. Last pic is Hornady brass loaded with 42.7 grain of RL16 under 140 ELDM's and 210M primers.
I have worked up a load with hornady brass and went up to 43.4 and was getting cratered primers, none pierced, I did not load but 20 or so at the 43.4.
I have worked up a load with hornady brass and went up to 43.4 and was getting cratered primers, none pierced, I did not load but 20 or so at the 43.4.
So my experience with LRP VS SRP I have a RPR 6.5 and when I shot LRP Hornady Brass and pushed a warm load the primer would crater and the same load on SRP the primer would crater and some times puncture. Velocity was the same and the bolt wasn't any harder to lift. Just simply there wasn't enough material to give around the larger firing pin found in the RPR. Sent the bolt to get bushed and the firing pin machined down and now I have no issue with either primer and in fact the primers don't crater at all. The cratering is all about how loose the firing pin is to the bolt. The benefit I see to SRP is that my Hornady brass LRP pockets will loosen up after 3ish firings on warmer loads. But my SRP cases of Starline and Lapua hold up to more abuse. Personally I don't like cratering it happens without the rest of the primer flattening so it's not overpressure.
LPR with stock RPR large firing pin
Pre bushed firing pin on top and post bushed and machined firing pin on bottom
LPR with stock RPR large firing pin
Pre bushed firing pin on top and post bushed and machined firing pin on bottom
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