SmallCaliberCentral

Hi There, Not to sure about primer in general when reloading the 204. What should,nt and should be use around max loads. I can obtain the following brands of primers federal .205 winchester, which i have been using, cci br4 bench rest and federal gm 205m .Also does switching primer brands really make that much of a difference when you have worked up a nice load, group. Could a different primer than usual open up that 1/2 inch group by much what do you experienced reload think. much appreciated. oh sorry one more thing can a change bring a velocity increase as well.

I`ve used Winchester, CCI 400, Federal 205m, and Rem 71/2 primers in various loads in both the 223 and 204 finding they all work well depending on the load and rifle I`m shooting at th time. You might find a CCI gives the best resuplt with a 40gr bullet and H44895 in your 203 but, a WSR does better when switching to Benchmark with the same bullet. Only trying them will tell.
Avoid the Remington 6 1/2 in any high pressure cartridge such as these two though. It was designed for mild pressure cartridges like the Hornet.

Geoff. With the higher intensity cartridges like the 204R, 17-223, even the 20VT and a few others stick with the bench rest or mag style primers Fed 205M, Rem 7.5 as examples. They have thicker cups and will not pierce with those cartridges, where as the standard primers can. As for does it make a difference. It can, most times not alot with various brands and a given load, but some rifles it will,so you just have to test your loads and your rifle, to see how it reacts with various brands of primers. I have just stuck with Fed 205M and the Rem 7.5 primers and have not had any problems and it just saves time, energy and less hassle overall. At least that is my take and opinion. Bill K

Haven't done a huge amount of primer swapping and research, but I'll give you a few figures here for reference:
Sierra Blitzking 39gn, Federal brass, 27.7gn AR2206H (H4895), Base to Ogive 1.930", Ruger Hawkeye 20" barrel.

All the above with rem7.5 primer:
-3603
-3593
-3598
group - 1.27"

Same components as above but with CCI400 primer:
-3633
-3714
-3623
group - 0.85"

Not an extensive survey, but probably enough info there to show you the primer will make a difference.
Work up to your pet load again if you change primer. Especially if you're using CCI400 - thinner cup. I've had no issues with them, but others have blown them out using a mild load. Be careful

Some time back, both Precision Shooting Magazine and Varmint Hunter Magazine both ran different articles by different authors with photos showing the effects of the various brands of primers being ignited in the dark with a high speed camera.

The differences in flame height and intensity is really a wake-up call, as they are ALL different, and not just in terms of cup thickness. Once you work up a load with a certain primer, you must reduce the load at least 10% and work back up when changing primers....there really IS a difference.

In the 204R, my personal choice is the Rem 7-1/2 BR, same for my 20VT and 223's, but my 223 Ackley loves the Fed 205M....go figure.

+1 on using bench rest primers like Rem 7.5, especially since 204 handloaders tend to load powder up near max levels or higher. You might have a problem using ordinary primers at such high pressures.

Thanks Guys!, putting my mind at ease . As I was experiencing a few flat primers with cci400s
In the next round of reloads, I think I,ll use cci br4s, as being a bench rest primer they must be more constant from shot to shot. I still have some winchester,s I would rather not waste, Hopefully these will be ok. very addictive forum with a wealth of info. really impressed with all the help that is on offer. thanks

Geoff. Remember a few things.. Reloading is a fun addition to our sport, helps and allows most of us to shoot more, come up with better loads and save money (Overall compared to buying Commercial). However lot's of people let it over whelm them. Follow the advice in the manuals and if you err, err on the low side. Is reloading dangerous, it can be, but so can a hammer when handled wrong and you hit your thumb, etc. Just be cautious and work with various componets, slow and easy. You will have years of enjoyment and fun working with your equipment and firearms. Bill K

I agree with Rick in that there are several differences in them, but not about the 10%.

Dr. Denton Bramwell did a really informative paper on differences in Standard Vs. Mag primers; in relation to pressure.
I believe you can find a discussion about it over on shootersforum. Denton haunts that board from time to time.

You say that you worked a load up to MAX, with a particular bullet/powder/primer/case combination. Then you want to CHANGE something. You have already answered your question about "will it CHANGE something"

My experience falls in line with Bramwell's info. IF you have a nice accurate load(NOT MAX), changing from a Win primer to a CCI benchrest, will not catapult the pressure into danger. Again because you CHANGED something, you shouldn't expect groups, velocity, etc to be the same.

Here's a link I came across the other day. Made for some interesting reading.

http://www.sksboards.com/smf/index.php?topic=56422.0

Hedge wrote:Here's a link I came across the other day. Made for some interesting reading.

http://www.sksboards.com/smf/index.php?topic=56422.0

That is one of the better examples of information on primers, that I have read.. Goes along well with what most of us do. Especially with our little high intensity cartridges. Thank you for sharing that. Bill K

You're welcome, Bill.

Makes us all better reloaders when we gain more knowledge about our components.

Hedge...thanks for that link. Alot of very good info there I've not seen elsewhere. Good-un!

My pleasure, Rick.