Primers

[village idiot]

What affect does changing a primer have, would it / could it affect grouping sizes, I could'nt get my normal primers and so bought some magnum primers. Groupings seem to have been affected, previously under an inch, now inch and a half. Any info advice appreciated, Village Idiot

[col48]

What affect does changing a primer have, would it / could it affect grouping sizes, I could'nt get my normal primers and so bought some magnum primers. Groupings seem to have been affected, previously under an inch, now inch and a half. Any info advice appreciated, Village Idiot

 

hi -

 

 

yes and if you where right up the top end with powder,it could send you over.

MRY has a burn rate chart for primers, I'm sure when he reads this he will supply you with it.

 

ATB

Colin

[village idiot]

hi -

yes and if you where right up the top end with powder,it could send you over.

MRY has a burn rate chart for primers, I'm sure when he reads this he will supply you with it.

 

ATB

Colin

Calibre .243, am using 36gr of H4895, 80gr Nosler BT.

[stag1933]

Drop your powder charge by a grain or so and try again.

HWH.

[Ronin]

By using magnum primers, you effectively change the load characteristics.

 

The magnum primer is designed to burn hot and hard, in order to light slow burning magnum powders. Normal primers are not quite as fast / explosive burning because they are designed for use in medium / fast powders.

 

 

Stag could be right , try dropping your powder charge a grain or two.

 

Personally, I would bin the magnum primers and get the right ones, why bother working up a load with a different primer when the original one works well?

 

There are pleanty of places that will send primers through the post and they are cheap - JMHO

[village idiot]

Thanks chaps, thats all I need to know, did'nt realise primers could be sent through the post, VI

[col48]

Thanks chaps, thats all I need to know, did'nt realise primers could be sent through the post, VI

 

 

as far as i know you can not send primers through the post(normal). as they are explosive.

but you can pay extra and some company's will ship them, try reloading solutions,

 

ATB

Colin

[325WSM]

Sorry for the delay in replying.

 

Primers are as much a variable component as any other in reloading and can alter velocity and trajectory and therefore accuracy quite considerably.

 

I have long been an advocate of using primers in the same way as powder to vary a load with great effect.

 

We dont choose our case because one looks shinier than another but because of the chemical composition that is most suitable for our particular load. Neither do we choose a Powder just because the local shop has it on the shelf and so with Primers - choose your primer to do the best job possible for the load you are generating.

 

A change of primer can in some loads require a drop of 3 grains and the difference in velocity without any increase in pressure can equally improve by 100fps. Use your primers in the same way as your powder and you will be surprised at the difference your loads will provide.

 

Here is a basic heat chart - from top to bottom drop about 5-6% in powder and work from there.

http://img.photobucket.com/albums/v356/mry...erheatchart.jpg

Use it as a guide and add in your own primers when you have assessed them. eg, the Prvi Partizan Primers although burning approximately as hot as the Winchester range do because of their different construction not seem to require a reduction in powder when changing from say Remington. Try for yourself and let us all know your test results as it will expand the above chart considerably.

 

Use of Magnum primers is normally reserved for the Ball Powders but I am finding I can use them to great effect in the shorter stumpier cases such as the WSM and WSSM range of cartridges. Logically this should also be valid for the Benchrest PPC cartridges.

 

The same is true for the H4831 SC powder in 243 - A Federal Magnum primer seems to provide anything up to 120 fps higher velocities than standard primers yet seemingly without additional pressure.

BUT

do drop the powder weight and build up again.

 

 

In this months 'Handloader' I notice that Charles Petty has written an article on Primers and 223 accuracy - anyone who would like to read it email me at mry716@hotmail.com and I will send a copy.

 

 

 

I also have a copy of James Calhoon's article written in the 'Varmint Hunter' for october 1995 about Primers and Pressure which is well worth reading.

 

Please remember to drop powder weights when changing primers and do also remember that with the present hot weather you need to reconsider all those max loads and take out a little powder.

 

A 10 degree rise in temp requires a 5% decrease in powder. If we are going to get such varied weather in coming years it may be best to have a min, intermediate and max load to use dependant on weather temperature.

[village idiot]

325WSM, thanks for that info, I think I will take Andy Mass course, bin these and go back to original primers, I am not one for tinkering and experimenting too much, I am a lazy bugger and once I find something that works I tend to stick to it, thanks again, VI

[325WSM]

You may find primers a little difficult to get presently but should have no problems with the PP ones.

 

I find them fine and as consisitant as any with excellent ignition. However, one or two friends have found problems in seating them in some makers cases so take a Lee AutoPrimer and a few cases with you to try before you buy a lot.

 

M

[Ronin]

Why not take both advice and experiment - 325WSM's is as informed and accurate as anyone I know of.

[Andrew]

US Army Ordnance labs tested primer strength with regard to peak chamber pressures. These pressures were the pressure obtained before the bullet began to move.

 

Higher heat primers ignited more of the power charge during that period. This in turn generated more pressure which, in effect, changed the burning rate of the powder. The end results were higher pressures and lower or equal velocities. This is why some of use here have switched to pistol primers for the Hornet Lil Gun powder. We get higher velocities and less pressure. ~Andrew

[nuttyspaniel]

Just to put a spanner in the works!! I use remmy 9 1/2 mag primers with vetcan tu7000 to push a 95grn bullet 2950 fps!! Now I did work the load up myself and for accuracy I get clover leaf groupings at 100yds!!

 

edited tp keep panther happy

[Guest 308Panther]

Nutty,

You really are gonna throw a wrench into the plan!!!

 

Keyholing happens when a bullet tumbles and enters the target sideways.And is not a good thing.

Single holed groups would be a better way to describe a good load work up,

or the end results of.

 

I dont mean to be technical on the terminology, but just trying to keep confusion to a minimum.

 

308Panther

[village idiot]

Nutty, I love that avater, my wife used to have breasts like that, then the kids ate them. Andy, no offence, and I realise I could be cast out as a heretic, but I do not seek the perfect load, if it groups under an inch at 100yds, I am happy and I can do my job. Last night, I had my tea, watched the cricket highlights, walked the dogs, went out shot 2 foxes and back in bed by midnight, if I start experimenting, I'll be in my garage messing about with loads when I could be out killing something, which is what I get paid to do. It is also very rare I take a shot beyond 150 yds, thanks for the answers lads. VI

[Vermincinerator]

Although pistol primers have been successfully used in some of the smaller rifle cases it is a practice that should not be undertaken lightly.

The higher inertia of a rifle firing pin can easily pierce the thin softer cups of pistol primers causing high pressure expanding gases into the firing pin hole area resulting in possible damage to the rifle.

 

Ian.

[325WSM]

They are also a different height.