Your opinion of what is the closest substitute for Rem 7 1/2 primer

[VaniB]

In your experience, which of the WSR, BR4, or CCI400 primers is likely the closest duplicate to the Rem7 1/2 primer?

I did initial range tests of a new 221 Fireball rifle using Rem 7 1/2 primers with Lapua cases. The results were very accurate and promising using R7 powder or IMR4198 & Nosler 40BT bullets. However, I've experienced issues with the Rem primers protruding too far out of the pocket & not allowing the bolt to close. But WSR, BR4 & CCI400 all seated properly. I tried manually turning a pocket uniformer by hand which didn't eliminate the prob. I just as soon find another primer early on in the range test stage instead of having to start jacking around now power drilling the uniformer in an attempt to get the Rem primers to seat. It's easier just to use one of the other 3 primers which seat properly from the get go.

 

[David101]

The CCI BR4 or Federal Gold Medal Match are both really good primers and probably the most used by competition shooters,

 

[VaniB]

The CCI BR4 or Federal Gold Medal Match are both really good primers and probably the most used by competition shooters,

Yes, I am aware of the fancier names and designations of "Benchrest" and " Gold Medal Match" and their higher prices for a supposedly better/consistent primer, but I already started with Rem 7.5's and I'm really trying to best duplicate the heat and ignition intensity as close to the Remington as possible. Some primers burn hotter then others, and I'm simply trying to hang onto the same combustion characteristics so maybe I won't lose the fine accuracy I was getting. Of course I realize that there is no guarantees, but I need to pick one and was wondering if anyone knew the burn rate/intesity similarities involved. Thanks.

 

[dolek]

Here you go,this may help.

https://www.6mmbr.com/primerpix.html

 

[KMart]

I think the Winchester SR primer is very similar in performance to the Remington 7 1/2. I have used Win. SR primers recently and have gotten some good results. The Winchester primers were developed to light off ball powder in military rounds and should have a pretty robust flame front. I've not had any reliability problems with the Winchester SR.

 

[Dead Eye]

You may want to try getting some more of the Rem 7 1/2s from a different lot number. Just buy 100 go home and try them. If they all seat then go back and buy a supply of the same lot number. I had one lot of Federal that I had the same problem with. Some would seat some would not. Went to my cabinet found a different lot and was good to go. Nothing is 100%, 100% of the time. Although rare with quality components stuff happens in the manufacturing world. If the other lot works Remington may replace the bad ones.

 

[Steve Ladino]

In your experience, which of the WSR, BR4, or CCI400 primers is likely the closest duplicate to the Rem7 1/2 primer?

I did initial range tests of a new 221 Fireball rifle using Rem 7 1/2 primers with Lapua cases. The results were very accurate and promising using R7 powder or IMR4198 & Nosler 40BT bullets. However, I've experienced issues with the Rem primers protruding too far out of the pocket & not allowing the bolt to close. But WSR, BR4 & CCI400 all seated properly. I tried manually turning a pocket uniformer by hand which didn't eliminate the prob. I just as soon find another primer early on in the range test stage instead of having to start jacking around now power drilling the uniformer in an attempt to get the Rem primers to seat. It's easier just to use one of the other 3 primers which seat properly from the get go.

You could pop some primers off in a revolver/pistol without powder or bullet and get a rough idea as to report and flame column comparisons. The cci 450's are very very good small rifle primers if you hit em hard enough and have 23% more mix in them than stnd, also the WW are good as mentioned before and both are close to the Rem. 7 1/2's. I'm thinking these three primers must be able to ignite whatever powder the majors use weather Ball or stick, temp sensitive or not . My pick , CCI 450 .

 

[Doom]

CCI 450 or CCI #41. FGMM 205AR may fill the bill also.

 

[Walt Krafft]

Remington 7 1/2's have been my go to small rifle primer for years since I did an accuracy test with 10 different small rifle primers. How are you seating your primers?

 

[Doom]

The brisance of the Rem 7-1/2 is higher than the FGMM 205 and WSR and is considered a magnum primer. The CCI 450 and #41 are considered magnum by CCI. The #41 has reduced sensitivity for use in semiautomatic weapons with floating firing pins (AR).

 

[VaniB]

Thanks guys. I've got CCI 450 primers on hand, and will try those next if need be. Dead Eye, I used a caliper on 3 different lots of 7 1/2 primers, and they were the same height. ( I concede when I saw the measurements of the other two lots of primers were the same as my problem primers, I didn't bother wanting to start randomly opening new cartons of primers to try seating them. They're simply too tall.) I finally chucked my RCBS uniformer into my cord drill, and discovered it takes 5 seconds to shave each pocket down. It took a lot less time to grab my stuff, go downstairs, and walk into my garage to do the dirty deed, instead of all the time I spent complaining and resisting with the belief that I shouldn't have to do it. (because these same primers seated just fine in my Lapua 20Tac brass , and Rem 223 brass). The primers still don't 100% seat and allow some of the cases to stand up square on my table without wobble, but the primer now seats 99.9% in far enough that I can feed the case into my rifle chamber. I suppose I can uniform the pockets for 10 seconds with my drill instead of 5 seconds for 100% results. Thankfully, I know I'll only have to uniform each case just once. lol

Thanks again for the help.

 

[Zero333]

Cci450 is probably your best bet.

But yeah... I also chuck the primer uniforming bit in a cordless.
I've even used the uniforming bit to clean the pockets.

 

[Coyotefurharvester]

I thought primer pocket uniformers had a shoulder, either adjustable or fixed to uniform the pockets. I had an issue with some Nosler 22-250 brass, Rem primers to tall, CCI and Win seated fine. Ran the Lyman uniformer and now all Rem primers seat at least - .002.

 

[Bill K]

Try the CCI #41, I think it is the closest to the Rem 7.5 that you will find.

 

[jepp2]

Try the CCI #41, I think it is the closest to the Rem 7.5 that you will find.

Just a suggestion, any time you change any load component, go through load development to find what is the max load for your rifle is with your components. I test different primers quite often, and the last time I changed to 41's from 7.5's, my velocity jumped 100 fps. I don't normally see that kind of jump, but it did this time. Probably just a function of the particular powder I was using, but it was done using the same lot.

 

[VaniB]

Just a suggestion, any time you change any load component, go through load development to find what is the max load for your rifle is with your components. I test different primers quite often, and the last time I changed to 41's from 7.5's, my velocity jumped 100 fps. I don't normally see that kind of jump, but it did this time. Probably just a function of the particular powder I was using, but it was done using the same lot.

Yes, I keep careful notes for the bench & range. I don't hunt, and my main interest is target shooting accuracy. It's a tedious process where much of the day involves coming & going to the range, and then finalizing my notes about which load worked best and tweaking that load for better future performance. To try and save time and avoid needless testing of some primers, I seek input from those here who already know such things. Of course, there are many variables and the final range test is the last word.

BTW;

I power drill the Lapua pockets a good bit and many of the primers still don't fit!! I have to put the primed case back onto the rockchucker press and push onto that primer a second time to get it to seat 98%-99%. When doing this, the primers never looked flattened or distorted, so I'll keep doing it as required. This is a most perplexing problem I've ever encountered with Rem primers, and believe the Lapua Fireball cases are too shallow for a primer that is too tall.

 

[jepp2]

I have to put the primed case back onto the rockchucker press and push onto that primer a second time to get it to seat 98%-99%.

I have run into tight primer pockets on some brass (over the years). I hand prime everything. I "used" to use the Lee Ergo hand primer. And whenever I would encounter a tight primer pocket, I would hear a "snap", and the plastic feeder would break. Might be due to tolerance issues with the cast handle.

But, I grew tired of returning the busted parts to Lee for replacement. And I converted over to the 21'st Century hand priming tool (after going through an evaluation with the Sinclair tool from Brownells). And since the conversion I have encountered some tight pockets on Lapua 6mm CM brass. The 21'st Century seated the primers to the proper depth with no visible change in the appearance. And on all my brass the primers are seated much more centered and straight. Not that I had them going in sideways before, but a noticeable difference.

I only mention it since you prime on your RockChucker press.

 

[AckleymanII]

VaiB, 7 1/2 fills a niche like no other. It is a hot primer with a thick cup. CCI 450 is a LOT hotter. Many times I have found that the 71/2 groups smaller than the 450, many....

Winchester is a hot primer but has a thin cup.

I use a primer pocket uniformer on the Lapua on every firing, problem solved. Grit gets in the corners and does not allow the primer to seat fully.

 

[VaniB]

Jepp, I'm sure you are familiar with the RCBS rock chucker. As you know, the RCBS primer assembly is a separate device which is all metal and connects onto the press. If the leverage of the same 20" long ram arm that resizes my Weatheby 300Magnum brass can't fully seat a primer into a pocket, then nothing is going to seat that primer. Obviously, something else is wrong.

I suppose, the next thing I can try is to start drilling the uniformer into the pocket and not stop until circular brush marks caused by the back plate of the uniformer start scratching into the Lapua name. Then maybe enough brass from the pocket will have been finally removed. Of course, it might be easier for me to try CCI 450's at the range. But if you're like me, you would be reluctant to dump accurate loads with the Rem 7 1/2's that you already spent hours at the bench and at the range developing.

 

[foxguy]

Two possible solutions

http://www.xxicsi.com/primer-pocket-uniformer.html

https://www.brownells.com/reloading...rbide-primer-pocket-uniformers-prod34720.aspx

749-003-709WB
Small Rifle/Pistol Primer Pocket Uniformer

and a Handle for the Sinclair primer pocket uniformer

https://www.brownells.com/reloading...rimer-pocket-uniformer-handle-prod128613.aspx

and a Power adapter for the sinclair uniformer cutter

https://www.brownells.com/reloading...rmer-screwdriver-adaptor-prod33850.aspx?dym=y

749-003-709WB
Small Rifle/Pistol Primer Pocket Uniformer

I have found spec's that says the Remington Small rifle primers are .110 depth. It sounds like you would want a Primer pocket Depth of .118 possible a little more.