lands erosion

[deadidarren]

gday all hope this is the right spot for this mods please move if not .

i not long ago 8 or 9 months had a 260 rem built on a new rem 700 long action

and had a Aussie made MADDCO barrel fitted now AFAIK these hold some records

for bench rest , now the rifle is still shooting good out to 1200 yards but i have

been chasing the lands the last couple of months and was surprised to find have

lost 0.047" in 800 rounds .

now the load is not a hot one in this rifle (45g of H4350 130g vld burger at 2932

fps) . just wondering what you blokes are seeing in 800 rounds of use .


cheers

 

[AckleymanII]

That sounds about right! I hope you save the same bullet for measuring each time.

 

[deadidarren]

That sounds about right! I hope you save the same bullet for measuring each time.

yep it all go's in the bag , i thought i would get more life out of a 260 than a 7mm rem mag

not less i have mine hopped up a bit it has 750+ i only found 7 empty pill box's and i cant

remember how many amaxs i put through it and it just has a factory sendero barrel in it and

has only lost 0.021" but i have lernt something today so all good just looks like it will get

re barreled to a 308 for practice instead of the 260 .

i can't afford $900+ a year for a new one


cheers

 

[vahena]

Same here, I lost .021 also, with about 900 rounds. I was wondering why my 6 ppc was not shooting right. Reset my jam longer after testing, and all is well.

 

[savagedasher]

gday all hope this is the right spot for this mods please move if not .

i not long ago 8 or 9 months had a 260 rem built on a new rem 700 long action

and had a Aussie made MADDCO barrel fitted now AFAIK these hold some records

for bench rest , now the rifle is still shooting good out to 1200 yards but i have

been chasing the lands the last couple of months and was surprised to find have

lost 0.047" in 800 rounds .

now the load is not a hot one in this rifle (45g of H4350 130g vld burger at 2932

fps) . just wondering what you blokes are seeing in 800 rounds of use .


cheers

Using QL as a reference that load looks to be very hot.
The only thing that melts metal is high heat or with extreme pressures low heat
Most powder burn temp wise with the same pressure close to the same. H4350 shows around 13''barrel would be where most of the hi pressure is.
Rl 19 with same speed shows you can lower the pressure 3000PSI gain 5 more inches to put the heat in..
MY thinking if you want to slow land erosion lower the pressure and increase the amount of the barrel the pressure is . Larry

 

[deadidarren]

when i developed the load i went up as i do looking for pressure and didn't find any all the

way up to 47.5g and 3111fps just a flat primer easy bolt lift , now there was just 4 loads at

that and then i settled on the 45g as it groups .5moa at 1000y for 3 .

now the cases have been loaded 8 times and the primer pockets are still tight to my way

of thinking i should be good to go and it is how i load for my 223 243 2506 260 7mm rem

mag and others and have never run in to this much erosion before .

it still groups so i will have it set back as the 130g burgers are just sitting in the mouth of

the case by about 0.060" just thought i would ask the question to see if it was something

peculiar to the cal.

cheers and thanks for the reply's .

 

[savagedasher]

Using QL as a reference that load looks to be very hot.
The only thing that melts metal is high heat or with extreme pressures low heat
Most powder burn temp wise with the same pressure close to the same. H4350 shows around 13''barrel would be where most of the hi pressure is.
Rl 19 with same speed shows you can lower the pressure 3000PSI gain 5 more inches to put the heat in..
MY thinking if you want to slow land erosion lower the pressure and increase the amount of the barrel the pressure is . Larry

Larry -

How can you predict his internals to be "very hot" when you don't know his seating depth, throating, ba levels to match his powder, actual case volume, and other particulars?
Myself, I've loaded +45gr. H4350 with 140's without excessive pressures.
So what gives, actual results or QL's predictions?

Donovan Assuming the question ask. With the speed he gave stated. Adjust the barrel from 24 to 30'' and the seating depth. from 2.800 to 2.300 not taking the effect the adding pressure the of jamming all the pressures shown on QL are hot. How could any one get a actual predication without more impute.
demoran we had this discussion last night. Larry

 

[savagedasher]

Using QL as a reference that load looks to be very hot.
The only thing that melts metal is high heat or with extreme pressures low heat
Most powder burn temp wise with the same pressure close to the same. H4350 shows around 13''barrel would be where most of the hi pressure is.
Rl 19 with same speed shows you can lower the pressure 3000PSI gain 5 more inches to put the heat in..
MY thinking if you want to slow land erosion lower the pressure and increase the amount of the barrel the pressure is . Larry

Take the bullet speed and use his powder drop and the bullet Working of the bullet speed with speed being as a reference build backward. Larry

Larry -

How can you predict his internals to be "very hot" when you don't know his seating depth, throating, ba levels to match his powder, actual case volume, and other particulars?
Myself, I've loaded +45gr. H4350 with 140's without excessive pressures.
So what gives, actual results or QL's predictions?

Donovan Assuming the question ask. With the speed he gave stated. Adjust the barrel from 24 to 30'' and the seating depth. from 2.800 to 2.300 not taking the effect the adding pressure the of jamming all the pressures shown on QL are hot. How could any one get a actual predication without more impute.
demoran we had this discussion last night. Larry

 

[dkhunt14]

Some barrels just erode faster then others. Some calibers the same thing. I have had barrels from one company erode .035 in 350 rounds and some from another company go less then half that with the same cartridge, loads and round count. Matt

 

[savagedasher]

.........and the seating depth. from 2.800 to 2.300

Going down to 2.300 seating, no wonder your getting excessive pressure predictions, the bullet would be like "all in".
Besides, 2.800" is short for long throated 260's with VLD's. And your still missing several other key particulars.
Regardless, his actual results to case stretch, primer pockets, and pressure sign, all trump QL predictions.

Your no doubt trying to be helpful, but when your computing with out all the actual particulars, predicting internals is like predicting floods.
Donovan

OH WELL 3.000

 

[deadidarren]

OK would you like over all length of with the Sinclair nut


cheers

 

[deadidarren]

OK would you like over all length of with the Sinclair nut

cheers

If you want him to give you QL predicted data, you better give him all your actual specifications:
- case volume (H2O capacity of your spent cases)
- Cartridge Over-All Length
- case length
- bullet location to lands
- bullet OAL
- powder & charge
- adjusted Ba levels that your powder Lot reacts
- barrel length (to bolt face)
- estimated pressure offset to your rifle barrel,primer used, and neck tension (things QL does not account for)

Even with accurate specifications, QL is still just a mathematical prediction and not at all factual or proven.

Good Luck
Donovan

yep that's why i don't have that or a loading book that's less than 25 years old haha

but they tell me that reading primers is like reading tea leaves ...... but it has worked

for me for all the other rifles i have loaded for .