Throat erosion - just pressure or powder type?

[ColinR]

I have often wondered if throat erosion is exacerbated only by the effect of pressure or if certain powders burn hotter than others and will erode the throat even at lower pressures. Any thoughts will be appreciated.

[20series]

I think its more the powder than pressure, theres a lot of debate about double based powders Vit 500 series etc causing faster burn out rates in barrels.. its the old story you can't have it all ways extra velocity is likely to mean more wear and tear..

Alan

[ovenpaa]

Double base powders do seem to erode the throat a bit quicker however do not look on this as a limiting factor for running such powders. If you are running an over bore cartridge such as necked down SAUM or 6,5-284 then you are going to see faster throat erosion as a matter of course, equally you can get many accurate shots from a .308 running DB powders.

A good example is my AI, chambered in 7,62x51 I put many thousands of relatively hot (155 Scenar/47.5+ grains of N540) through it and it still shoots remarkably well, now compare it to a 7mm SAUM which is going to be over the hill at 750 rounds.

I did hear recently of an F/TR .308 shooter re-barrelling at the 1000 round mark however this is truly excessive and I would be concerned about more than just throat erosion if I needed to fit a new barrel after so few rounds through a .308

[ColinR]

Thanks for the input. My basic concern was that I understand .338LM can burn a barrel out in around 2000 rounds. I use 88.5grains of N165 for reloading .338LM, in preference to N560, so presumably I will get some degree of benefit using this single base powder and a not too hot load.

[ovenpaa]

I assume you are using the Lockbase or something of a similar weight as 88.5 grains is quite a load. I have shot with people using factory Lapua Match in the TRG42 .338LM and they have to get considerably more than 2000 shots out of a barrel, they train out toi 2500m with such ammunition. The .338LM is never going to be easy on the barrel or action regardless unless you drop the load significantly which does tend to take some of the fun out of shooting it.

[ColinR]

I assume you are using the Lockbase or something of a similar weight as 88.5 grains is quite a load...

I am using 250 grain Lockbase - this load is certainly the top end for N165 with a quoted velocity of 2906fps, but not confirmed by chrono. It is also quoted by Vihtavouri as an 'Accuracy load' - seems to shoot well - I worked up to this from 83.5 grains and it does work well. I wonder however if I should not change to Scenar 250 and a lighter load in the interests of economy (Barrels).

[ColinR]

David I had a long look at your website today - I did not realise you had a Weimaraner dog. I have had four over time, but latterly have had a couple of Rotties. I have to say compared to the last two Weimars, Brahms & Liszt, they are absolute saints. My Weimars seemed to hate everyone, everything.......used to try and kill other dogs on shoots between drives, absolute menaces, but hugely loveable and loyal. The Rotties on the other hand love everyone and are just big softies. The one I have now invariably comes to Bisley with me. Apart from all that a great site, very interesting. Colin

[ovenpaa]

My Weimars seemed to hate everyone, everything.......used to try and kill other dogs on shoots between drives, absolute menaces, but hugely loveable and loyal. The Rotties on the other hand love everyone and are just big softies...

Blue is affectionately referred to as the Dog from hell. He is a lovable chap and frighteningly loyal to Christel which can be a problem when she is out with him as all other dogs, horses, pigeons and people mean her ill and need to killed. He has no issues with cats or sheep.

He will join me in the shed in the afternoon when the sun peeps in through the doorway and sleep next to the milling machine regardless of how much noise I am making, but if a stranger walks up the lane he is up, barking and ready to lay down his life for us.

Weims are very special creatures and I can honestly say I have never known another dog like him.

As far as the .338LM goes, that much N165 behind the 250LB is an ideal and from a personal view point I would not consider dropping it back any, after all it is what it was designed for and if the Danes are anything to go by you should get a fair few rounds through it before having to worry about barrel wear.

[Gun Pimp]

Thanks for the input. My basic concern was that I understand .338LM can burn a barrel out in around 2000 rounds. I use 88.5grains of N165 for reloading .338LM, in preference to N560, so presumably I will get some degree of benefit using this single base powder and a not too hot load.

Wow - 2000 rounds - I had a look at one the other day that was absolutely goosed at around 1500!
Vince

[ColinR]

Thanks for the input. My basic concern was that I understand .338LM can burn a barrel out in around 2000 rounds. I use 88.5grains of N165 for reloading .338LM, in preference to N560, so presumably I will get some degree of benefit using this single base powder and a not too hot load.

Wow - 2000 rounds - I had a look at one the other day that was absolutely goosed at around 1500!
Vince

I know they get through barrels but 1500 rounds??? Are stainless barrels better or worse? I have an AI with an SSteel Walther barrel and expected at least 2000 rounds out of it.