New super quarterbore bullets

[stagpanther]

Hornady recommends a faster than 8 twist for these bullets. And yet they are not key-holing on your target. I have a 700 Rem Classic that I have wanted to try them in, now I think I will.

I ordered my barrel with a 1:7 twist. That said, I suspect if you drive them fast enough you'll get adequate results out to a fair range--there's a guy on Utube who's firing the 135 gr bergers out of a 1:10 twist 257 weatherby and he claims he's getting great results out to long range. He might also be burning out his barrel real fast, too. Anyways, love to see your results. What is your .257 cartridge?

[stagpanther]

The utility company moved their trucks out of the way this morning so I was finally able to "stretch my legs" a bit and shot at 218 yds. It was gusty about 15 mph+ from 8:00 but the treeline seemed to help some. Unfortunately one of the cartridges failed to fire--I've had 2 FTF of these in about 100 cartridges--I'm using CCI LR bench rest primers but I seem to be having a problem with them seating too deeply.

[scatterbrain]

I have a 25-06 which is #5 for me, I like them, but it does have the 1:10 spin. I have mostly shot 100 grain bullets and have taken several deer with them and a truck load of woodchucks. Are you able to maintain the recommended COL with the 134 grain bullet.

On the above unfired bullet I would check for a light strike of the firing pin.

[stagpanther]

I have a 25-06 which is #5 for me, I like them, but it does have the 1:10 spin. I have mostly shot 100 grain bullets and have taken several deer with them and a truck load of woodchucks. Are you able to maintain the recommended COL with the 134 grain bullet.

I haven't shot the 134 eldm in a 25-06--but have shot the 133 berger hybrid in a 25-06--there was plenty of room to spare to seat it adequately and I'm sure you'll experience the same with a 134 eldm. I didn't see any key-holing with my 1:10 twist 25-06; but the grouping wasn't very good, that may be just because I didn't use a good load and the barrel itself is pretty old and worn out.

On the above unfired bullet I would check for a light strike of the firing pin.

Thanks for that. I actually replaced the main spring in the bolt with a new stiff one--my impression is that it might be actually hitting the primers too hard. It doesn't happen when I use Federal or genix LR primers, only these; but I really like the consistency and ignition properties of the CCI BR primers. I recycled the cartridge a couple of times to see if it would go--that's more than one firing pin strike on it.

[stagpanther]

Tried a few of the 110 gr bulldozer 2s from Badlands--it's a pretty radical bullet considering it's only 110 grs and .257 caliber. I was surprised to learn that it's actually a hunting bullet.

The shape of the bullet is kinda lie an hourglass with a waist much as Jim Watson says. Problem is--I have no idea where the optimal case mouth position should be. Most monolithics have drive bands of one type or another that function as areas of bearing surface and have specific positions in seating--but I'm stumped as to how this one is supposed to work. So I seated with the case mouth behind the "waist."



For a preliminary test I chose a load of 55.4 grs of RL22, a bit on the low side but this is "exploration" and I didn't want to take chances. Even so, the bullets were flying along at 3,370 fps; I suspect the full power ones will easily eclipse 3,400 fps and get close to 3,500 fps. Unfortunately I'm about out of RL22 so I'll have to finish testing with some other powder (been a long time since I've seen it in stock anywhere).



I've been carefully timing my shots and never get the barrel hot--rarely even warm. I took a look with my borescope today and couldn't believe the fire-cracking to the throat and first 5 inches or so of the bore--I mean it's noticeably worse than it was just a 100 cartridges ago. I have also been careful to stay well-away from top-end hot loads. I have maybe 400 shots down the tube but I don't think this barrel is going to make it much past 600 the way things are going.

[stagpanther]

Perhaps UncleNick would like to weigh in on this--but I see a potential big issue with what I've been doing here and possibly others that are doing development in the 25 PRC or 25 7mm PRC.

I started out using "normal" jacketed calculations for the 134 eldm in Quickload (weigh factor of .5 and pressure start of 3625) but my velocities were typically far in excess of what QL returned with those settings. I had to make my own inputs of default measurements in QL since the 25 PRC isn't in the database of cartridges. I wasn't getting any unusual pressure signs in the brass; other than the occasional "clicker" when I used CCI BR-2 primers--but I was seeing very fast degradation in the throat and bore, even though I was using charge weights well under what QL was saying max.

When I changed the weight factor to .33 for overbore bottleneck cartridges I got almost a perfect match for the predicted velocities--but a very significant jump in peak pressures well past the recommended max chamber pressure. I can't say for sure how accurate the predicted pressures are without measuring them--but judging from the accelerated wear in the bore and throat I'm inclined to think I've been under the illusion (as perhaps others have) that the 3,200 fps and more which is easily attainable might in fact be straying into much higher pressures than people think. For the eldm I stayed well under that but still saw significant fire-cracking degradation in the barrel.

Based on those "suspicions"--I'm going to try to dig deeper into this and would recommend against using the loads I've tried.

[Jim Watson]

I seem to be having a problem with them seating too deeply.

I once had a .25-06; the RP brass had excessively deep primer pockets and a bottomed primer would not always fire. I seated them flush and they all fired but there was probably an adverse effect on velocity and accuracy. I just wasn't a good enough loader and shooter at the time to tell.

[stagpanther]

I once had a .25-06; the RP brass had excessively deep primer pockets and a bottomed primer would not always fire. I seated them flush and they all fired but there was probably an adverse effect on velocity and accuracy. I just wasn't a good enough loader and shooter at the time to tell.

I switched to cheaper genix primers and have had no issues--I could be imagining things but the groups seem to have opened up a hair. With my calipers the outside size of the two primers seems to be identical--yet the genix primers definitely sit higher in the primer cup of the case (?).

[stagpanther]

For the "If it ain't at least 10 shots it didn't happen" set I whipped up 10 cartridges of the 134 ELDMs just to see what they would do--it actually was prompted by the arrival of the first truly warm and sunny day here on coastal Maine this year. The winds however were a gusty 15 to 20 quartering headwind, but they still did remarkably well.

Two of the wide shots I know I pulled as they broke--but 6 of the first shots were touching and made a group under .4 MOA. The other wide shots were mostly me or because the barrel was getting hot--I've learned that it can be cool to the touch on the outside and still be getting torched on the inside.

I'm very impressed by this bullet/cartridge combo for its consistency--but as far as I can figure you're going to need deep pockets for frequent barrel replacements if you shoot it for more than 10 shots at a time; maybe even less.