260 Rem Load Worries

[atlsniper6.5]

Gents,

I got my custom 260 build back and started load work up this weekend. My best group was less than .25 MOA with the hottest load that I tested:

140gr Berger Hybrid seated .005 off the lands (2.214 OAL measured from Ogive)
44.5 grains of H4350 getting 2960 fps
New Lapua Brass
Fed 210M Primer
26" Krieger M24/M40 Contour 1:8"

No signs of pressure, but I am still a little worried. I feel like the reloading manuals low ball this cartridge by a ton when they give the so called "max load." Should I back off a little bit or quit whining and enjoy my new Joe Collier nail driver?

Thanks,
Patrick

 

[Gray]

Truthfu8lly I would back off a little bit. I have always shot lapua brass and have usually started to see pressure at 43gr w/ H4350 and a 140. Not sure how you are not seeing at least a firm bolt lift with that load. Most shoot around 42gr H4350 with Lapua brass. This should net around 2800-2850 w/ a 26' barrel. Even if your load isn't producing noticeable pressure signs, you definitely want a load that will work in 100 degree weather and pouring down rain. Unless you have a 30" barrel, 2960 is a little too fast for the 260, and probably will result in poor brass life.

 

[atlsniper6.5]

Truthfu8lly I would back off a little bit. I have always shot lapua brass and have usually started to see pressure at 43gr w/ H4350 and a 140. Not sure how you are not seeing at least a firm bolt lift with that load. Most shoot around 42gr H4350 with Lapua brass. This should net around 2800-2850 w/ a 26' barrel. Even if your load isn't producing noticeable pressure signs, you definitely want a load that will work in 100 degree weather and pouring down rain. Unless you have a 30" barrel, 2960 is a little too fast for the 260, and probably will result in poor brass life.

Nope, nothing. Bolt doesn't stick at all.

 

[lte82]

Nope, nothing. Bolt doesn't stick at all.

Mind posting a picture of the bottom side of the brass? Also, are the bullets moly coated? Barrel length / brand?

A buddy got some naked 139 scenars up to 29xx in his 27" tube with a little overpressure, but I think he backed it down to a high 2700 low 2800 node to extend brass life. 2750-2800 fps will still get you out to 1300-1400 supersonic no problem at sea level.

 

[atlsniper6.5]

Mind posting a picture of the bottom side of the brass? Also, are the bullets moly coated? Barrel length / brand?

A buddy got some naked 139 scenars up to 29xx in his 27" tube with a little overpressure, but I think he backed it down to a high 2700 low 2800 node to extend brass life. 2750-2800 fps will still get you out to 1300-1400 supersonic no problem at sea level.

No moly coating on the bullets. Barrel is a 26" Krieger M24/M40 Contour 1:8". I will post some pictures of the brass when I get home. There could definitely be some signs that I have not yet experienced, and wouldn't know what to look for.

 

[vinsonr]

No moly coating on the bullets. Barrel is a 26" Krieger M24/M40 Contour 1:8". I will post some pictures of the brass when I get home. There could definitely be some signs that I have not yet experienced, and wouldn't know what to look for.

I think I'm getting loose primer pockets in my 43gr 4350 load, 140 amax, lapua brass, 210m primers. Prep your fired brass and see if seating a primer is much easier than previously. I see a noticeable difference in virgin brass or my other load of 41.5gr and the 43gr load.

Vinson

 

[milo 2.0]

Anyone else's loads, or data is irrelevant in your barrel-chamber, action combo. Without pressure trace equipment you have no idea what pressures you're building. I would keep upping my charge till you get an ejector mark, or a stiff bolt, all the while chronoing it. I helped friend pressure up a new 260 last week, I think it was 45.5 gr, H4350, Lapua brass, where we got an ejector mark, settled on just under 44gr for load.
Lapua brass is exceptionally hard to figure pressure marks, and sometimes only a pierced primer will be your only sign. Until a person actually finds his pressure point, how will you ever know?

 

[RyeDaddy]

You're up in 6.5-284 territory, brother. I wouldn't run it that hot. 6.5-284 speed from a cartridge with less capacity = barrel and brass life shorter than 6.5-284.

For reference I'm running 42 grains and getting 2800 from a 24" barrel. I have no pressure signs at the next node up (43.3) but the 140's are running 2890 FPS there and I feel THAT's too warm.

Side story: A guy at my shooting club I talk to regularly had a custom 308 that he was thrilled to be running 175 SMK's at 2850 from with a 22" barrel.... Using Lapua brass he had "no pressure signs" at all. Brass went 5 firings (I think) which I thought was low for Lapua, and one day he came up there with a new 260 barrel on it. In talking with him, the 308 barrel had gone tits up at less than 3k rounds.

I don't think there are any miracles of physics out there is what I'm saying.

 

[HodgdonExtreme]

Anyone else's loads, or data is irrelevant in your barrel-chamber, action combo. Without pressure trace equipment you have no idea what pressures you're building. I would keep upping my charge till you get an ejector mark, or a stiff bolt, all the while chronoing it. I helped friend pressure up a new 260 last week, I think it was 45.5 gr, H4350, Lapua brass, where we got an ejector mark, settled on just under 44gr for load.
Lapua brass is exceptionally hard to figure pressure marks, and sometimes only a pierced primer will be your only sign. Until a person actually finds his pressure point, how will you ever know?

All good points.

Still, if most everybody is running between 2775 and 2875, and you are getting 2960... You need to ask yourself why.

Is my scale correct? Is my chrono correct? Is my ability to determine high pressure good enough? Do I just have an extraordinarily fast barrel? Am I just smarter than everybody else? Braver?

 

[atlsniper6.5]

All good points.

Still, if most everybody is running between 2775 and 2875, and you are getting 2960... You need to ask yourself why.

Is my scale correct? Is my chrono correct? Is my ability to determine high pressure good enough? Do I just have an extraordinarily fast barrel? Am I just smarter than everybody else? Braver?

Definitely why I made the post... You have to follow the gut

 

[Danco411]

I did load testing yesterday too. 24" LW-50 1:8 twist barrel. 140g Hornady Amax with H4350, once fired Lapua brass and CCI BR2 primers. COAL 2.90. I ran my batches from 43-45 in .5 increments. Magnetospeed V2 Chrony.

43 - 2690 FPS
43.5 - 2720 FPS
44 - 2760 FPS
44.5 - 2830 FPS
45 - 2865 FPS

Absolutely no pressure signs whatsoever. The 45g brass looked identical to the 43. All were laser like accurate with the 44.5 being just mildly better at 100.

I also did some testing with Alliant's Power Pro 2000MR. Alliant only shows two loads for this in .260. A 95g and 120g SP bullet. The loads were rediculously low to the point where I think it was an afterthought. I run 47g of 2000MR under my 175g SMK load in .308. So why would a 120g .260 load be only 40g?

I worked up from 40 to 44 in 1g increments with the 140 Amax. Same brass and components as above.

40 - 2610 FPS
41 - 2690 FPS
42 - 2720 FPS
43 - 2780 FPS
44 - 2815 FPS

Again no pressure signs whatsoever. I am going to run the 2000MR up to 46 or 47 to see what it does. It too was really accurate. If I can get the 2000MR to run 2900 with no pressure that may be a keeper!

 

[milo 2.0]

All good points.

Still, if most everybody is running between 2775 and 2875, and you are getting 2960... You need to ask yourself why.

Is my scale correct? Is my chrono correct? Is my ability to determine high pressure good enough? Do I just have an extraordinarily fast barrel? Am I just smarter than everybody else? Braver?

This is why I tried to explain that he needs some kind of pressure identification. I've seen a good number of fast combo's over the years, they're a fluke, but damn fun. C. Dixon just built me a 6.5 Creed that I think will push 130's at 3000fps, I'm gonna run it and love it! And the Berger he's running has a lot less bearing surface than my bullet.

 

[milo 2.0]

All good points.

Still, if most everybody is running between 2775 and 2875, and you are getting 2960... You need to ask yourself why.

Is my scale correct? Is my chrono correct? Is my ability to determine high pressure good enough? Do I just have an extraordinarily fast barrel? Am I just smarter than everybody else? Braver?

Most of the people in your statement wont veer away from H4350 either, there's a fuck of a lot more and faster powders out there. VV N550, H100V, RL 17, if you need to live inside the box, die there!

 

[lte82]

Most of the people in your statement wont veer away from H4350 either, there's a fuck of a lot more and faster powders out there. VV N550, H100V, RL 17, if you need to live inside the box, die there!

Don't forget varget, and don't forget that it doesn't take speed to win a match.

Sherri Gallagher Uses .260 Rem to Win National HP Championship « Daily Bulletin

 

[rcamuglia]

Gents,

I got my custom 260 build back and started load work up this weekend. My best group was less than .25 MOA with the hottest load that I tested:

140gr Berger Hybrid seated .005 off the lands (2.214 OAL measured from Ogive)
44.5 grains of H4350 getting 2960 fps
New Lapua Brass
Fed 210M Primer
26" Krieger M24/M40 Contour 1:8"

No signs of pressure, but I am still a little worried. I feel like the reloading manuals low ball this cartridge by a ton when they give the so called "max load." Should I back off a little bit or quit whining and enjoy my new Joe Collier nail driver?

Thanks,
Patrick

Most everybody who has replied to you thinks that every lot of H-4350 has the same burn rate.


Wrongo.


I shoot the 139 Scenar from my Creedmoor and have used H-4350 for years. The lots vary. I had one lot where 41.3 grains was the load and had a velocity of 2750. Pressure was found at 42 grains. The lot I'm shooting now I went to 45 grains before pressure signs were found. My load had 2 nodes; one at 43.5 grains and one at 44.8 grains. The 43.5 grain load is my load and I'm getting 2925 fps out of a 26" barrel

If you are not having a sticky bolt lift, ejector marks on your case heads, you're good to go.

 

[Wildwillalaska]

Every gun is different, but question is how different. I would 2nd processing your brass to see how your primer pockets are holding up.

I am using the same ammo combination, 140 Berger Hybrids, H4350, in Lapua 260 brass, with Federal Match large rifle primers. I found pressure shy of 44 grains. Settled in on 42.9gr of H4350 which pushes the 140 Hybrids at 2800 fps out of my Hospitaller, which has a barrel measured 24" from front of the action.

BUT, that is loaded to magazine length giving it about .028" jump. I don't have my ogive measurement handy to compare, so not sure how much case capacity you may have freed up by loading out to .005" off the lands. As a side note, ogive measurements may well vary depending on whether your using a Hornady or Sinclair comparator--they have different size holes for some reason.

 

[atlsniper6.5]

Every gun is different, but question is how different. I would 2nd processing your brass to see how your primer pockets are holding up.

I am using the same ammo combination, 140 Berger Hybrids, H4350, in Lapua 260 brass, with Federal Match large rifle primers. I found pressure shy of 44 grains. Settled in on 42.9gr of H4350 which pushes the 140 Hybrids at 2800 fps out of my Hospitaller, which has a barrel measured 24" from front of the action.

BUT, that is loaded to magazine length giving it about .028" jump. I don't have my ogive measurement handy to compare, so not sure how much case capacity you may have freed up by loading out to .005" off the lands. As a side note, ogive measurements may well vary depending on whether your using a Hornady or Sinclair comparator--they have different size holes for some reason.

Thanks, sir. I am using the Hornady Comparator. 2.214 just barely fits in my AI Mag. I would be interested to hear your Ogive Measurement.

 

[Dezelrig]

I recently loaded some 139 scenars using new Lapua brass. I pushed the bullets to 2950 FPS.

When I went to reload the cases for the second firing, the primers slid in way too easy. Too easy. The brass didn't exhibit external signs of over pressure on the first firing.

I'm thinking I just trashed a lot of $1/piece brass.

 

[Sniper260]

I'm still working on my 260... I havent been able to get it right yet. Using H4350, berger 140's, federal match primers, lapua brass. I got some loads worked up that I need to test, but its been so damn windy everyday that I cant find a good chance to load test... I'm not one to test precision loads in even 10+ mph wind... and its been a good 20+ for the last few weeks...

 

[17874]

I run 41 grains of H4350 and get 2739 out of my 26" Shilen. I am still using Federal Gold Medal Match .308 Brass that I sized down to .260. when I first made the switch to .260. I have five loads on the brass now and after annealing I should get five more......Hopefully with such a light load, I should get over 2K on this barrel.

 

[Sniper260]

What is an around about barrel life of a 260? Shouldnt they go over 3k rounds and be close to what a 308 does?.. I mean assuming you dont run hot loads...

 

[Sniper260]

When I first got my 260 I ran a ladder test all the way up to 45gr of H4350 which was over published max... I didn't have pressure signs, but I didn't have any accuracy either... they didn't group. Hopefully I will get the sweet spot here between 41gr and 42 gr... I have .2 gr increments loaded up to test. I've been trying like crazy to get this thing to shoot one hole groups out to 200 yards... and my best node is in this area right here ladder test wise... I thought H4350 would be the perfect powder for it.. But I may have to try a different powder if it doesn't split hairs... with H4350 I havent been able to keep a consistent "under half and inch" at 200 yards. I'm a stickler though... as of right now my 200 yard targets are what I would accept at 300...

I've been shooting these berger 140VLD's though and I am wondering if I should just try a different bullet and see what happens, or a different powder and see what happens.. frustrating..

 

[HodgdonExtreme]

I recently loaded some 139 scenars using new Lapua brass. I pushed the bullets to 2950 FPS.

When I went to reload the cases for the second firing, the primers slid in way too easy. Too easy. The brass didn't exhibit external signs of over pressure on the first firing.

I'm thinking I just trashed a lot of $1/piece brass.

Precisely why I bring reloading gear, and do load workups @ the range with only a handful of pieces of brass.

That way you can load/fire the same piece 5+ times very quickly in just one range visit to validate the load.

 

[djskit]

I'm perfectly happy with 2800 - 2850 in my 260 or 6.5 CR shooting 139 scenars out of a 26 inch barrel. I've never gone over (nor have any of my immediate aquiantences ever gone over) 43.5 grains of H4350. My current load is 43.3 at 2820.

Can it be done safely? I don't know for sure but I do not feel the need to find out. If I really wanted to drive 139s over 2900, I'd get a rifle chambered in a round that can easily handle it like a 260 AI or something similar.

 

[atlsniper6.5]

Here are pictures of all of the case heads. Minimal difference from 42 gr to 44.5 gr:

The only thing I notice is a difference in the diameter of the primer on a few of them. Example:

Looking back at the data it looks like I was around 2850 with 43.5 gr. I'll go back and see how tight of a group I can string together with that.

Here was the three shot group at 100 with 44.5:

It measures .46 edge to edge, minus .260.


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[Wildwillalaska]

What is your build? Fair amount of flattening between the two cases in the second photo. Good example picture of cratering too--but I have had a couple bolts that just seem to crater every federal primer they touch. Not sure if softer cup, bigger firing pin hole, or combination of both--but on those weapons, cratering is worthless indicator of pressure.

Here however, you also have clear flattening and some fair amount of primer flow. That case is pretty much what I would expect one to look like if it were to push a 140 hybrid 2940-ish fps.

Sometimes reading brass for pressure almost seems like reading tea leaves--folks see what they believe they want to see. That my non-expert opinion anyway.

 

[Gray]

Here are pictures of all of the case heads. Minimal difference from 42 gr to 44.5 gr:

The only thing I notice is a difference in the diameter of the primer on a few of them. Example:

Looking back at the data it looks like I was around 2850 with 43.5 gr. I'll go back and see how tight of a group I can string together with that.

Here was the three shot group at 100 with 44.5:

It measures .46 edge to edge, minus .260.


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Yeah those primers are cratered pretty good. You do not want the raised up edge around where the firing pin strikes the primer. You should be able to run your fingernail over the spent primer without it snagging. Back down to 42gr and go up in .1 gr increments until you find the perfect load. You should find it between 42-43 gr, I wouldn't go over 43.

 

[atlsniper6.5]

Here are a couple factory Winchester primers from when this rifle was a 308. This bolt just craters them to a certain extent.

I am definitely going to back off though.


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[atlsniper6.5]

What is your build? Fair amount of flattening between the two cases in the second photo. Good example picture of cratering too--but I have had a couple bolts that just seem to crater every federal primer they touch. Not sure if softer cup, bigger firing pin hole, or combination of both--but on those weapons, cratering is worthless indicator of pressure.

Here however, you also have clear flattening and some fair amount of primer flow. That case is pretty much what I would expect one to look like if it were to push a 140 hybrid 2940-ish fps.

Sometimes reading brass for pressure almost seems like reading tea leaves--folks see what they believe they want to see. That my non-expert opinion anyway.

Build is a Rem 700 SA, trued up, lugs lapped.

Krieger M24/M40 Contour 1:8 @ 26"

McMillan A-5 in Olive Marble.

Surgeon Bottom Metal

Badger 20 MOA base

Seekins Precision Low 35mm rings

Vortex Razor HD




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[HodgdonExtreme]

Some bolts crater primers with any load, pretty much. However, the 308 primers you posted are NOT especially cratered, while the stoutly loaded 260 primers are wildly cratered.

Danger, Will Robinsin, danger...

 

[Wildwillalaska]

Checked when I got home, I am loading to an ogive measurement of 2.215" using the Hornady comparator. Barely fits into the mag and still functions. My above load at this measurement produces right at 2800 fps in my rifle.

 

[Danco411]

BTW Hodgdon now rates 44.5 of H4350 as max load.


Start Speed Pressure Max Speed Pressure
H4350 .264" 2.780" 41.5 2,590 50,100 PSI 44.5 2,735 58,000 PSI

I still think this is conservative. Is not max pressure for the .308 case over 60,000 PSI? At 44.5 I get 2830 FPS and 45 2865 with no pressure signs at all. Nothing like the cratering shown above. But that may be his firing pin. My Lapua cases at 45 look just like the ones at 43. I may try bumping up to 46 in smaller increments although I don't really need to. I'm very happy with the accuracy at 44.5 and 45.

 

[malsa82]

No one here is using RL17?

 

[milo 2.0]

No one here is using RL17?

I am in a Creedmore, and a 6.5x47, but let's don't hijack this thread.

 

[atlsniper6.5]

BTW Hodgdon now rates 44.5 of H4350 as max load.


Start Speed Pressure Max Speed Pressure
H4350 .264" 2.780" 41.5 2,590 50,100 PSI 44.5 2,735 58,000 PSI

I still think this is conservative. Is not max pressure for the .308 case over 60,000 PSI? At 44.5 I get 2830 FPS and 45 2865 with no pressure signs at all. Nothing like the cratering shown above. But that may be his firing pin. My Lapua cases at 45 look just like the ones at 43. I may try bumping up to 46 in smaller increments although I don't really need to. I'm very happy with the accuracy at 44.5 and 45.

Can you send me the link where Hodgdon published that?


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[Danco411]

Can you send me the link where Hodgdon published that?


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Plug in 260 Remington with 142g Bullet.

Take Aim at Rifle Reloading Data | Hodgdon Reloading

 

[atlsniper6.5]

260 Rem Load Worries

Plug in 260 Remington with 142g Bullet.

Take Aim at Rifle Reloading Data | Hodgdon Reloading

That is interesting. The data is conflicting. They show the max load with the 140 at 42 grains.


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[vinsonr]

That is interesting. The data is conflicting. They show the max load with the 140 at 42 grains.


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Different bullets have different shapes and that drives different internal ballistics. Nosler 140 partitions have a longer bearing surface than 140 amax and 142 smk. They are also not boat tails so that reduces case volume when seated to the same
depth as the amax or smk.

 

[RyeDaddy]

That's because the 140 in question is a Nosler. Long bearing surface = more pressure. The 142 SMK although heavier has a shorter bearing surface. The data was correct at the time they tested and with the lot of powder they had at those times. All things are variable and bullet shape affects pressure to a good degree. Another bullet in the same weight range but a different shape could show a totally different max.

I tend to watch velocity as more of an indicator of pressure than anything, as well as measuring expansion at the case head. In the Hodgdon data, if I see what their max velocity was with a similar bullet using similar brass, I expect that within 100 FPS of the data is probably within acceptable limits of pressure. If I see velocities much higher than 100 FPS+ I back off whether or not I have noticeable pressure signs. I figure I'm causing undue wear somewhere whether I notice that day or not. Just my way of doing things.

To comment on your brass pics, those primers look flattened to me but that is not a reliable indication in my experience. Primers look just as flat with mild loads if you have too much headspace (shoulder bumped too far), and most of my Remingtons crater primers due to large firing pin hole. Only way I *try* to judge pressure examining brass on those rifles is by measuring expansion at the case head just above the extractor groove vs brass fired with known safe loads or by pressure required to remove/install primers. With really hard strong brass like Lapua this may not happen as early.

I may be seeing it wrong, but is there an ejector swipe on the case on the right in the one pic? I'm browsing on an iPhone so it's hard to tell. A shiny swiped mark? That is a no-no also, but I've never see those without having seen loose primer pockets first.

 

[atlsniper6.5]

Different bullets have different shapes and that drives different internal ballistics. Nosler 140 partitions have a longer bearing surface than 140 amax and 142 smk. They are also not boat tails so that reduces case volume when seated to the same
depth as the amax or smk.

That makes sense.


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[atlsniper6.5]

I guess this is the point where I ask if anyone would be nice enough to plug the specs in to Quickload to give me an estimate of the max load with my components.


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[rcamuglia]

Yeah those primers are cratered pretty good. You do not want the raised up edge around where the firing pin strikes the primer. You should be able to run your fingernail over the spent primer without it snagging. Back down to 42gr and go up in .1 gr increments until you find the perfect load. You should find it between 42-43 gr, I wouldn't go over 43.

Those primers are cratered because of an oversized firing pin hole in the bolt.

 

[HodgdonExtreme]

Those primers are cratered because of an oversized firing pin hole in the bolt.

Disagree.

OP posted primer pictures from 308 ammo fired from the same bolt, prior to rebarreling to 260. Those 308 primers show little to no cratering, meanwhile the 260 primers have crazy cratering.

I'm well aware of the cratering typical of many Remingtons and other actions with oversized firing pin holes. Regardless, it takes a lot of pressure to get them to flow like his are.