Winchester Primers to Blame?

[kamikaze]

I have been hand loading for .308 for about 2 years and recently purchased a new Remington 700. I'm in the process of working up a load and have been getting sub par (0.8-1.1 MOA) results in comparison to my old Remington 700P (0.2-0.6 MOA). Other than the fact that I'm using a different rifle and optic I'm trying to eliminate possible causes for the poor performance in the hand loaded ammunition first. It shoots factory Hornady 165 gr TAP ammo really well at 100 yards (~0.5 MOA). Last year I used up all of my CCI #200 primers and purchased Winchester Large Rifle primers.

Are CCI primers necessary for small groups? Should I expect sub par results from Winchester primers?

Here is my current load data:
Lapua brass full sized
Winchester large rifle primer
Lapua 155 gr Scenar
Hodgdon 8208 XBR - 45.2 grains

I know there are all kinds of different variables at work here but I'm looking for information regarding a comparison between CCI and Winchester primers. Thanks.

 

[RyeDaddy]

Re: Winchester Primers to Blame?

There's no hard evidence that Winchester primers are inherently less accurate than others that I've seen. In fact one of my rifles (45-70, a very different beast) has lower velocity spreads with Winchester LR over the BR-2's I use in other rifles, and it shoots fantastic. Lots of shooters here use Winchester.

Changing primers has the least effect on accuracy in my amateur experimenting, but your mileage may vary. It'd be a relatively cheap experiment to go pick up 100 CCI's if you have a store close by that stocks them and try again and see what difference you get, I know others would be interested in reading results.

If you were near me I'd trade you some.

 

[Gene Poole]

Re: Winchester Primers to Blame?

How did you come up with this load in the first place? Did you use a ladder test, or OCW? If not, those are the best ways to determine the sweet spot for a particular rifle. If you did use OCW or ladder, then any change in the components (primers, cases, even seating depth) may result in falling out of your node.

 

[1lnbrdg]

Re: Winchester Primers to Blame?

I've always had good luck out of the Winchester primers.

 

[redbullitt]

Re: Winchester Primers to Blame?

They work fine for me. I have interchanged them without any issues with cci 200 in 260 rem, 308 win, 30 30, and 243. I will say that they seem to show cratering a bit faster than the cci in my experience.

 

[kamikaze]

Re: Winchester Primers to Blame?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gene Poole</div><div class="ubbcode-body">How did you come up with this load in the first place? Did you use a ladder test, or OCW? If not, those are the best ways to determine the sweet spot for a particular rifle. If you did use OCW or ladder, then any change in the components (primers, cases, even seating depth) may result in falling out of your node. </div></div>


Yes. I used the ocw method.

 

[Todd629]

Re: Winchester Primers to Blame?

At this point primer brand would be the least of my worries. You are working up a load for a different rifle so it is not a given that anything close to your old combinations will shoot well. Have you checked scope mounting,bedding, got an acceptable trigger etc.

 

[kamikaze]

Re: Winchester Primers to Blame?

Thanks everyone for your help on this.

I'm not using my old combination load data. It was in the 42 grain range with a 168 grain smk bullet, which, I refuse to use due to their inferior ballistics at longer ranges.

With this rifle I've tried 175 Federal GMM, 175 Black Hills Match as well as the 165 Hornady TAP. The TAP shot the best of the factory loads with GMM really close in performance. The Black Hills was over 1 MOA. All ammunition is being tested at 100 yards using a bipod and rear sand bag rest.

The rifle is in a chassis and still has the factory barrel and X-mark trigger tuned as light as it can be within the factory specs. Scope is mounted perfectly in a Larue Tactical 1.5 QD style base/rings combo.

The 8208 is supposed to be very consistent with velocity but my current load had an ES of 42 FPS 2 days ago. I will get some CCI primers and see if that makes any difference in the velocity consistency.

 

[Todd629]

Re: Winchester Primers to Blame?

kamikaze,
You might also try some Varget or IMR-4064. 4064 has worked well in every 308 I have ever worked with except one, that one came around just fine with a stiff charge of Varget. Years ago, my first custom varmint rifle refused to shoot better than 1 moa with what I considered my "go to powder" for that caliber, a change to another similar speed powder and suddenly I had the sub 1/2 moa rifle I had hoped for.

 

[Oneteam]

Re: Winchester Primers to Blame?

I wouldn't suspect Win primers. They are shooting about .5MOA in my 20" 308 as well. I would try adjusting seating length first.

 

[kamikaze]

Re: Winchester Primers to Blame?

More jump possibly? I currently have them seated as long as the AICS magazines will allow give or take a few thousandths. I've heard the Scenars like to jump but they are already jumping over .030". I'm not going to seat them so long that I can't use them in another rifle if necessary.

 

[kamikaze]

Re: Winchester Primers to Blame?

Thanks for the info. I may try that as I have both powders available, but only in 1 pound containers. I really don't feel like working up a load only to have to work up another load in 4 months when the 1 pound I have on hand is gone. I have 12 pounds of 8208.

 

[big45guy]

Re: Winchester Primers to Blame?

Might want to try ball c short cut as well

 

[shoot4fun]

Re: Winchester Primers to Blame?

I am not sure that 8208 is a good choice for the 308 with 175 gr bullets.
I agree that you should try other powders like Varget.
Just because a load you used to shoot in another rifle worked well doesn't mean much to a different rifle.

 

[BuzzBoss915]

Re: Winchester Primers to Blame?

Well, considering that everything is different, if I understand correctly, powder, bullets, and rifle? I have to wonder how you focused on the primer, which, as somebody already observed, is probably the least of your concerns?

You had a 700P that was shooting .200" groups but you must have lost it or something? You know that .8/1.1" groups are about all you can expect from a factory rifle, right?

Working up a load from a 1 pound bottle of 4064, then running out four months later would require a <span style="text-decoration: underline">very small</span> adjustment, if any, should you need to buy more. It's not like starting over with a complete unknown. In my experience, at least.

Where did you hear that Scenars like to jump? Every rifle is a law unto itself, but that sounds like an urban legend, to me? You shouldn't have a preconceived notion about what works and what won't. A universal starting point is ten thou off the lands and go from there unless you have magazine restrictions? BB

edit: I just thought of a reason why Scenars, (or any other bullet) might like a "jump". Perhaps because the load is borderline excessive and the freebore helps to keep the pressures down a tad?