RS 62 vs RS60

[Ronin]

Those with long memories may remember back to 1993, when a batch of ammunition made by Lapua was used in the Easter meeting. The ammunition had been loaded to a little under the maximum CIP pressure to ensure it performed at long range, but the fact that target rifle barrel dimensions were (and still are) a few thou' tighter than the CIP pressure barrel in which the ammo was tested (and which was made to minimum CIP specs) meant the ammo was over-pressure in most target rifles in use on the day. There were dropped primers and stuck cases galore, but for one individual, Brian Lewis, the consequences were much more serious. The back end of the case let go, his modern target rifle of European origin was not designed to handle gas escapes safely and he ended up with a face full of brass particles.

He would have been much safer had he used a Mauser 98 action, designed over 120 years ago, but which is a tour-de-force in action design to safely handle catastrophic cartridge case failure. See Stuart Otteston's masterly two books on "The Bolt Action Rifle" for a forensic examination of gas handling safety in action design.

Be that as it may, this is an incident will happen again while the NRA persist in allowing target rifles with dimensions that are smaller than CIP, and the Proof Houses carry on condoning it.

As for small rifle primers, I see that the Target Shooter magazine features an article by David Tubb on his XC cartridges, which are designed for a working pressure of 80,000 psi...!!

A recipe for catastrophic failure

 

[welshwarrior]

Thabks for the comprehensive post Laurie (as always)

Yes I’m familiar with the tighter bores used with TR and have built a few F class guns over the years (mainly open class guns )

It’s always a worry when one sees threads such as this where the op is chasing a velocity to achieve rather than using what they can safely attain

Many try to emulate internet proclamations of hyper VO with no substance (dangerously so)

The advent of small primer brass does not help the situation as the laws of physics can’t easily be changed

Without high pressure, one will not attain high velocity but the containers used (cartridges and chambers) will only stand so much beating before they bite back

This to me is one of the reasons maintain issued ammo in TR is a plus whilst after 2018 & 2019 ammo issues don’t aid this.

The fact Palma teams all use ammo loaded by one man (at his company) in a singular recipe suggest that it’s not the huge advantage some portray it as to chase perfect load for each rifle under 1000 yards.

F Class MR And FTr of course go further back and have mostly scope to enhance accuracy again.

 

[borbal]

The fact Palma teams all use ammo loaded by one man (at his company) in a singular recipe suggest that it’s not the huge advantage some portray it as to chase perfect load for each rifle under 1000 yards.

F Class MR And FTr of course go further back and have mostly scope to enhance accuracy again.

The bull is just under 2 MOA wide for Palma TR shooters, whereas it is just under 1 MOA for F Class shooters.... I would suggest you are comparing apples with oranges

 

[borbal]

was this the case that lead to the introduction of rule 150 on chamber sizes?

Well, it led to a much tighter specification of chamber sizes in Rule 150, effectively creating a "308 Bisley" cartridge, with the tacit admission that it might not be safe to shoot CIP approved 308 Win ammo in a TR rifle made to Rule 150 specs. But as Laurie was explaining in another thread on 6.5 x 55 ammo, having two types of the same cartridge, one for "proper" CIP dimensioned rifles and one for rifles in which using such ammo might generate dangerous pressures, (albeit for different reasons), is a recipe for mishap.

 

[welshwarrior]

The bull is just under 2 MOA wide for Palma TR shooters, whereas it is just under 1 MOA for F Class shooters.... I would suggest you are comparing apples with oranges

A little but I would suggest the scope on the F Class rifle more than accounts for 1 MOA

 

[borbal]

A little but I would suggest the scope on the F Class rifle more than accounts for 1 MOA

Ha! I recall Mik Maksimovic challenging Andy Luckman that if Andy could produce a tighter group than him at 1000 yards, he would eat his hat.

Mik lost that challenge....

 

[scrumbag]

This to me is one of the reasons maintain issued ammo in TR is a plus whilst after 2018 & 2019 ammo issues don’t aid this.

The fact Palma teams all use ammo loaded by one man (at his company) in a singular recipe suggest that it’s not the huge advantage some portray it as to chase perfect load for each rifle under 1000 yards.

F Class MR And FTr of course go further back and have mostly scope to enhance accuracy again.

Hmmm. Are these rifles all built and chambered to shoot a known bullet - load combo though? I rather suspect they are.

Scrummy

 

[welshwarrior]

Ha! I recall Mik Maksimovic challenging Andy Luckman that if Andy could produce a tighter group than him at 1000 yards, he would eat his hat.

Mik lost that challenge....

Not like Mik Mak

 

[welshwarrior]

Hmmm. Are these rifles all built and chambered to shoot a known bullet - load combo though? I rather suspect they are.

Scrummy

Scrummy

they are built to fire a 155 grain bullet most commonly used is a Sierra but they also use a Berger for 900 and 1000.

I have some of this ammo and it shoots brilliantly in my Mauser 98, Remi 700 and a friends T3 with shorter barrels 20/24/22” but we normally only go back to 600x holding the bull if we do our bit not bad for old hunting guns!

 

[Laurie]

I've never understood why TR rifle barrels have remained undersize compared to the SAAMI 0.300/3080" standard. It made sense, alongside one turn in 14 twists, when trying to coax some semblance of performance out of the old 145gn FMJBT 'Green Spot' 7.62 Nato military round, but that was a long time ago now.

Now that most everybody uses decent ammo with the 155gn Sierra MK (O/D c. 0.3083" whenever I measured one) or in the States the Berger 155.5 BT alongside the newer SMK, why stick with it? References in American forums suggest their 'Palma' discipline sling shooters often use it too which makes even less sense as I don't think they ever used issued military grade ammo in their matches.

 

[welshwarrior]

I've never understood why TR rifle barrels have remained undersize compared to the SAAMI 0.300/3080" standard. It made sense, alongside one turn in 14 twists, when trying to coax some semblance of performance out of the old 145gn FMJBT 'Green Spot' 7.62 Nato military round, but that was a long time ago now.

Now that most everybody uses decent ammo with the 155gn Sierra MK (O/D c. 0.3083" whenever I measured one) or in the States the Berger 155.5 BT alongside the newer SMK, why stick with it? References in American forums suggest their 'Palma' discipline sling shooters often use it too which makes even less sense as I don't think they ever used issued military grade ammo in their matches.

I’ve asked the same question and just the answer because it works!

 

[borbal]

I've never understood why TR rifle barrels have remained undersize compared to the SAAMI 0.300/3080" standard. It made sense, alongside one turn in 14 twists, when trying to coax some semblance of performance out of the old 145gn FMJBT 'Green Spot' 7.62 Nato military round, but that was a long time ago now.

Now that most everybody uses decent ammo with the 155gn Sierra MK (O/D c. 0.3083" whenever I measured one) or in the States the Berger 155.5 BT alongside the newer SMK, why stick with it? References in American forums suggest their 'Palma' discipline sling shooters often use it too which makes even less sense as I don't think they ever used issued military grade ammo in their matches.

A very good question!

The answer, in part, is to try and get better performance out of 308 Win ammo at long range. But because 308 Win ammo might produce dangerous pressures in TR rifles built to Rule 150 specs, the ammo is downloaded to ensure it does not produce high pressures. The virtuous circle is thus complete and we may as well go back to a standard CIP spec barrel and ammo and save a lot of potential safety problems.

But the other part of the answer is that the NRA sells its specially downloaded ammo to a captive market. You might say that the NRA in consequence have a vested interest in maintaining Rule 150 as it stands for commercial reasons. I couldn't possibly comment...

 

[scrumbag]

I think there are 2 parts to this:

1) There is a lot of intertia around TR shooting in general.
2) There is something of a cottage industry around building TR rifles and some of the "myth" I think suits them...

 

[welshwarrior]

But the other part of the answer is that the NRA sells its specially downloaded ammo to a captive market. You might say that the NRA in consequence have a vested interest in maintaining Rule 150 as it stands for commercial reasons. I couldn't possibly comment...

I wonder if a lead ban effects target shooting if the use of Non Lead will bring a change to the Rule 150 in TR?

 

[Malxwal]

@gixer1, you lost this one

 

[Edinburgh Rifles]

I’ve recently run up some loads with RS62 and still not quite at the velocities I was trying to hit (around 2850fps) for a 6.5CM with 24” barrel.

I’m loading 123gr fox copper,

you dont need it
I have shot Fox in 4 cartrdges for over 4 years now
the most I shot was 150gr 308 at 2650fps

They work just fine at MV of 26-2700
That said you shouldnt have a problem reaching 2850 with a 24"

 

[gixer1]

you dont need it
I have shot Fox in 4 cartrdges for over 4 years now
the most I shot was 150gr 308 at 2650fps

They work just fine at MV of 26-2700
That said you shouldnt have a problem reaching 2850 with a 24"

Yes, I know...I contacted fox and posted the info on here a few months ago...

 

[D13REW]

Good Morning,

I can't help you with the fox 120 and 140grn with RS60 but have some interesting results with Fox 100grn and RS60. If it helps drop me a line and I can open my spread sheet when I get home. Load development for better grouping is still ongoing but i have shot roe deer no problems at all with this combo.

Cheers

 

[Cambridge Pimpernel]

Good Morning,

I can't help you with the fox 120 and 140grn with RS60 but have some interesting results with Fox 100grn and RS60. If it helps drop me a line and I can open my spread sheet when I get home. Load development for better grouping is still ongoing but i have shot roe deer no problems at all with this combo.

Cheers

Hi there. Would be really interested to know the combo. Am about to load Barnes TSX 130s ahead of RS60 in .270. I am betting fine for Reds, but probably a little punchy for roe and muntjac. Was thinking of 90-100gr bullets ahead of RS60 for them. Any Copper bullet recommendations? Thanks

 

[D13REW]

Hi there. Would be really interested to know the combo. Am about to load Barnes TSX 130s ahead of RS60 in .270. I am betting fine for Reds, but probably a little punchy for roe and muntjac. Was thinking of 90-100gr bullets ahead of RS60 for them. Any Copper bullet recommendations? Thanks

Hello mate,
I've told a lie and haven't fired my loaded 100grn fox copper with RS60 yet, they are in my box ready for the next range trip. I've been using the fox with n550 with 3 roe dropped on the spot no issues. I have both the fox and Barnes 100 ttsx loaded ready to try. If I can be of any further help let me know