Eggleston 9mm coated oal?

[ericuda]

Just received some eggleston 125 grain coated rn bullets for 9mm. I loaded a dummy round for my cz-75 and decided to post the pictures on my concerns/questions.

The oal had to be extremely short (1.050) to pass the plink test. The bullet has an extremely long bearing surface and a short blunt rn.

The picture has the dummy round, a 124 xtreme plated rn loaded to 1.135, sized cases sitting on top of the coated and a 124 xtreme rn for comparison.

I am thinking of loading some up with 4.2 cfe pistol which is below starting but for the short oal it would be safe load.

What does everyone think of the short oal? I have other 9's but always load for the shortest chamber since I don't want "gun" specific loads for plinking.

 

[CZ9shooter]

Bullets with wide ogives or of truncated cone style need be seated deep in the CZ75. I used to load a lot of XTPs. They had to be at the very short recommended OALs that we see in most manuals for XTPs. I load mine at 1.065. But in my other 9mm handguns I could load them about as long as anything else.

So short is somewhat normal. I dont have experiance with the powder you mention though so I cant comment on that. Just make sure you start low. And will that fat bullet profile cycle well, at that short length, in all guns? I dont know. Only one way find out.

 

[sl33py]

I had similar issues/concerns with some hi-tech coated 135gr 9mm. TC - i found by testing in my 3 9mm barrels that i needed a OAL/COL of 1.09x or less for the most restrictive one. (trying to recall from memory - i think it was 1.097 or 1.095 - definitely on the verge of the "minimum" COL). FYI - Loaddata shows Minimum COL of 1.095.

I'm a bit paranoid about over-pressure, so knowing that i'm at a reduced volume, possibly increasing pressure - I did a very conservative ladder of charge weights in .2 increments up to the mid-range and checked primers on each before moving up. I had great success, no issue cycling, and a great "plinking" round with titegroup and 700x (700x was a bit dirtier, but i'm also at mid-charge or less which doesn't help).

 

[Wreck-n-Crew]

Yeah the Nose on that RN is short compared to most of what you see and it evidently seats deeper.

I am thinking of loading some up with 4.2 cfe pistol which is below starting but for the short oal it would be safe load.

That's what I would do.

 

[LiveLife]

eggleston 125 grain coated rn ... 9mm ... cz-75 ... oal ... 1.050"

I am thinking of loading some up with 4.2 cfe pistol which is below starting

I think that's a good idea. I have not used that particular bullet but it looks similar to MBC 124 gr RN with shorter nose and longer base that needs to be loaded shorter for my barrels (and even shorter for CZ barrels as reported by many).

I used 1.080"-1.100" as my working OAL for load development and due to bullet base that's seated deeper than published load data for Cone Nose (look at bullet base lengths in comparison picture above), I reduced my start/max charges by .3 gr. Initial powder tested was W231/HP-38 and while Hodgdon listed 3.9/4.4 gr as start/max charges for Lead CN @ 1.125", I started at 3.6 gr and tested 3.8/4.0/4.2/4.4 gr loads.

Range test with .355"-.356" groove diameter barrels resulted partial/full-length barrel leading from 4.2/4.4 gr loads. Recoil from 3.6 gr load was mild and 3.8/4.0 gr loads produced greater accuracy without leading that I ended up using.

Hodgdon load data - http://www.hodgdonreloading.com/data/pistol

125 Lead CN CFE Pistol Dia .356" 1.125" Start 4.4 gr (1,041 fps) 27,200 PSI - Max 5.0 gr (1,156 fps) 33,000 PSI

For CFE Pistol, this thread tested MBC 125 gr SWC in CZ P-09 with CFE Pistol @ 1.066". Chrono data showed the below with some post comments that 1100 fps loads produced better accuracy - http://www.czfirearms.us/index.php?topic=72670.15

4.4gr 1060 fps (SD 15)
4.5gr 1077 fps (SD 14)
4.6gr 1084 fps (SD 11)
4.7gr 1119 fps (SD 9)

If you compare MBC RN to SWC bullet lengths, 1.050" with RN should be above the seating depth of SWC tested for chrono data.

Since slower than Unique/Universal powders obtain cleaner burn/optimal accuracy at higher charges, I would suggest starting out at 4.2 gr and testing 4.4/4.6 gr loads then see how accuracy trends and go from there.

 

[ericuda]

Thanks all, I'll load up 10 at 4.2 and 4.4 and see how they run over the chrono and for accuracy. I think i have some mbc rn around somewhere that i will compare to seating depth too. Looked odd to me seated that short. I hope they will feed reliably and i'll note that too.

 

[Dudedog]

Different bullet but here are some numbers with different OALs in 9mm All bullets the same RMR FN.

5 vels the average, the ES, SD and PF

Springfield 1911 9mm 5"
S+B SP Mixed brass
4.0 HP38 OAL 1.065
RMR 124gr FN 5 vels , Avg vel, ES, SD, PF
1045 1031 1040 1040 1033 1037.80 14 5.72 128.6872

4.0 HP38 OAL 1.10
RMR 124gr FN 5 vels , Avg vel, ES, SD, PF
1004 997 1021 1025 1021 1013.60 28 12.32 125.6864

4.2 HP38 OAL 1.065
RMR 124gr FN 5 vels , Avg vel, ES, SD, PF
1065 1088 1079 1066 1072 1074.00 23 9.62 133.176

4.2 HP38 OAL 1.10
RMR 124gr FN 5 vels , Avg vel, ES, SD, PF
1077 1062 1063 1055 1071 1065.60 22 8.53 132.1344

4.4 HP38 OAL 1.065
RMR 124gr FN 5 vels , Avg vel, ES, SD, PF
1116 1111 1103 1107 1109 1109.20 13 4.82 137.5408

4.4 HP38 OAL 1.10
RMR 124gr FN 5 vels Average ES SD PF
1099 1113 1112 1098 1116 1107.60 18 8.44 137.3424

More difference here velocity wise at the lower charges.
I am not trying to say a shorter OAL is safe pressure wise, just throwing out some data for you to consider.

 

[tcoz]

I find that it's a lot easier to determine OAL for different bullets by using a bullet comparator. Pick one that shoots well in your gun, measure the ogive to base length of a dummy round and use this to set your seating depth for other bullets. You still have to make sure that you have an appropriate amount of bullet seated within the case but for most bullets this procedure works well.