7mm bullets, 180 hybrid, 183 Sierra 195 Berger

Get or give advice on equipment, reloading and other technical issues.

Moderator: Mod

Message
Author
RDavies
Posts: 1904
Joined: Sun Feb 12, 2006 7:23 pm
Location: Singleton NSW

7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#1 Postby RDavies » Tue May 10, 2016 8:25 am

Bullets from left are Berger 180gn Hybrid, Sierra 183gn, Berger 195gn

Image

Berger 180gn Hybrid, Sierra 183gn Berger 195gn stood on their nose to show ogive length difference.

Image

I took some basic measurements of these 3 bullets and this is how they compare.

Berger 180gn Hybrid Sierra 183gn Berger 195gn
OAL 1.515" 1.600" (+.085") 1.645" (+.135")

BTO .660" .685" (+.025) .775" (+.115")

BS .480" .475" (-.005") .590" (+.110")

BT .180" .210" (+.030") .185" (+.005")

Ogive .855" .915" (+.060") .870" (+.015")

Dia .2846" .2836" .2839"

These bearing surface measurements are only comparative, taken with 2x bullet comparators, no high tech bearingsurfaceometers used.

I only did basic checks for uniformity across 20 bullets of each type, so not statistically significant.
From the brief checks I did, the 180 hybrids varied around .006" in BSL, the Sierras around .002" and 195s .008"

These measurements are for interest sake only and not exact, rounded off a thou or two.

AlanF
Posts: 6779
Joined: Wed Jun 15, 2005 8:22 pm
Location: Maffra, Vic

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#2 Postby AlanF » Tue May 10, 2016 8:46 am

Very good info Rod - thanks for sharing. Where did you source the Sierras? They would appear from the measurements and from the appearance of the ogive to have significantly less drag than the 180 hyb, so with the higher weight should have a better BC. The only thing I don't like is the smaller diameter - may not suit all barrels?

RDavies
Posts: 1904
Joined: Sun Feb 12, 2006 7:23 pm
Location: Singleton NSW

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#3 Postby RDavies » Tue May 10, 2016 9:10 am

AlanF wrote:Very good info Rod - thanks for sharing. Where did you source the Sierras? They would appear from the measurements and from the appearance of the ogive to have significantly less drag than the 180 hyb, so with the higher weight should have a better BC. The only thing I don't like is the smaller diameter - may not suit all barrels?

Yes, the smaller diameter might be a concern. The fat Hybrids have gone extremely well in a few barrels of mine, I am not sure how many barrels will like the 183s.
Some other things to consider before people get all giddy over the measurements is that you will need an 8.5" or faster to use the 2 new bullets. My 9" twist barrels have all gone for a long time between cleaning but my faster twist barrels have had some issues with fouling, whether it is just random luck, or could the faster twist have something to do with it?
The other consideration of faster twists is if you are running a fast magnum, the rotational speed might be getting close to the bullets structural limit. Will you get blow ups as I have heard of one person getting in Australia with the 195s pushed fast? You might have to keep the barrel throats in tip top shape to keep the bullets intact???

BTW, these diameters (and all measurements) were just with one batch of each bullet. I think my Hybrids are fatter than most batches, could my Sierras be smaller than average???

jasmay
Posts: 974
Joined: Fri Sep 28, 2012 9:26 pm

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#4 Postby jasmay » Tue May 10, 2016 9:32 am

RDavies wrote:
AlanF wrote:. I think my Hybrids are fatter than most batches, could my Sierras be smaller than average???


I've heard your a bit smaller than average.....

DenisA
Posts: 1414
Joined: Wed Nov 09, 2011 7:00 pm
Location: Sunshine Coast, QLD

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#5 Postby DenisA » Tue May 10, 2016 10:14 am

Awesome Rod. I like that the bulk of the difference is in the shank and the ogive length has not dramatically increased.

Has anyone checked the MV limit? I'm guessing its about 2840 - 2850 fps.

I'm guessing that might be a low node for a SAUM?

Depending on where the nodes are and how close it is to the MV limit, this might be perfect situation for barrel tuner?

willow
Posts: 165
Joined: Sat Aug 15, 2015 9:51 pm

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#6 Postby willow » Tue May 10, 2016 8:07 pm

RDavies wrote:
AlanF wrote:Very good info Rod - thanks for sharing. Where did you source the Sierras? They would appear from the measurements and from the appearance of the ogive to have significantly less drag than the 180 hyb, so with the higher weight should have a better BC. The only thing I don't like is the smaller diameter - may not suit all barrels?

Yes, the smaller diameter might be a concern. The fat Hybrids have gone extremely well in a few barrels of mine, I am not sure how many barrels will like the 183s.
Some other things to consider before people get all giddy over the measurements is that you will need an 8.5" or faster to use the 2 new bullets. My 9" twist barrels have all gone for a long time between cleaning but my faster twist barrels have had some issues with fouling, whether it is just random luck, or could the faster twist have something to do with it?
The other consideration of faster twists is if you are running a fast magnum, the rotational speed might be getting close to the bullets structural limit. Will you get blow ups as I have heard of one person getting in Australia with the 195s pushed fast? You might have to keep the barrel throats in tip top shape to keep the bullets intact???

BTW, these diameters (and all measurements) were just with one batch of each bullet. I think my Hybrids are fatter than most batches, could my Sierras be smaller than average???


Cheers for the info Rod. I have a 32" 8.5 twist barrel on order and was planning on trying the Sierra 183gr bullets. I was considering trying the 195s but not sure whether an 8.5 twist would be up to the task. It may be worthwhile buying 100 to see.

Any noticeable difference in accuracy/velocity between the 3 bullets?

RDavies
Posts: 1904
Joined: Sun Feb 12, 2006 7:23 pm
Location: Singleton NSW

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#7 Postby RDavies » Tue May 10, 2016 9:16 pm

willow wrote:
RDavies wrote:
AlanF wrote:Very good info Rod - thanks for sharing. Where did you source the Sierras? They would appear from the measurements and from the appearance of the ogive to have significantly less drag than the 180 hyb, so with the higher weight should have a better BC. The only thing I don't like is the smaller diameter - may not suit all barrels?

Yes, the smaller diameter might be a concern. The fat Hybrids have gone extremely well in a few barrels of mine, I am not sure how many barrels will like the 183s.
Some other things to consider before people get all giddy over the measurements is that you will need an 8.5" or faster to use the 2 new bullets. My 9" twist barrels have all gone for a long time between cleaning but my faster twist barrels have had some issues with fouling, whether it is just random luck, or could the faster twist have something to do with it?
The other consideration of faster twists is if you are running a fast magnum, the rotational speed might be getting close to the bullets structural limit. Will you get blow ups as I have heard of one person getting in Australia with the 195s pushed fast? You might have to keep the barrel throats in tip top shape to keep the bullets intact???

BTW, these diameters (and all measurements) were just with one batch of each bullet. I think my Hybrids are fatter than most batches, could my Sierras be smaller than average???


Cheers for the info Rod. I have a 32" 8.5 twist barrel on order and was planning on trying the Sierra 183gr bullets. I was considering trying the 195s but not sure whether an 8.5 twist would be up to the task. It may be worthwhile buying 100 to see.

Any noticeable difference in accuracy/velocity between the 3 bullets?
.
I have done very little testing on paper so far, mainly some shorting over a cronograph. Around 2830 fps with the 195s is about ballpark in a SAUM but you will need a decent length throat. I hope to run the 183s over a cronograph in the next week or so and will be expecting to get around 2950 safely.

Frank Green
Posts: 200
Joined: Wed May 28, 2014 11:48 pm

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#8 Postby Frank Green » Wed May 11, 2016 3:48 am

Here was the original post I did on the 183gr. Sierras when I got them. Might be some info. there to help you out still.

viewtopic.php?f=5&t=7453

To bring you up to speed I did shoot them out of my 1-9 twist barrel (.284win. chamber) on New Years Day. It was 28 degrees F outside (so just below 0 C) when I shot them. With no load work at all (used my normal 180 Berger load) and the gun shoot no group bigger than a .400" at 117 yards. I haven't had a chance to shoot them at any further distance as of yet.

The 4 boxes of bullets I got and I randomly pulled a couple of bullets and measured the o.d. of the bullets they mic'd .2840" for me.

Feedback I've gotten from The U.S. Team F Class Shooters is they (183 SMK) will shoot in cut rifled 9 twist barrels but won't shoot in the 9 twist button barrels.

I feel a 9 twist barrel will be to much on ragged edge of being stable and according to my twist calc's you need 1-8.5 min. So if I we're to build a gun from scratch/get a new barrel I would go with a 8.5 or a 8.25 twist. The 8.25 twist have been very popular as well.

Later, Frank
Bartlein Barrels

willow
Posts: 165
Joined: Sat Aug 15, 2015 9:51 pm

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#9 Postby willow » Wed May 11, 2016 5:37 pm

Frank Green wrote:Here was the original post I did on the 183gr. Sierras when I got them. Might be some info. there to help you out still.

viewtopic.php?f=5&t=7453

To bring you up to speed I did shoot them out of my 1-9 twist barrel (.284win. chamber) on New Years Day. It was 28 degrees F outside (so just below 0 C) when I shot them. With no load work at all (used my normal 180 Berger load) and the gun shoot no group bigger than a .400" at 117 yards. I haven't had a chance to shoot them at any further distance as of yet.

The 4 boxes of bullets I got and I randomly pulled a couple of bullets and measured the o.d. of the bullets they mic'd .2840" for me.

Feedback I've gotten from The U.S. Team F Class Shooters is they (183 SMK) will shoot in cut rifled 9 twist barrels but won't shoot in the 9 twist button barrels.

I feel a 9 twist barrel will be to much on ragged edge of being stable and according to my twist calc's you need 1-8.5 min. So if I we're to build a gun from scratch/get a new barrel I would go with a 8.5 or a 8.25 twist. The 8.25 twist have been very popular as well.

Later, Frank
Bartlein Barrels


Thanks for the info Frank, hopefully the 8.5 twist you're spinning up for me is up to the task 8)

Frank Green
Posts: 200
Joined: Wed May 28, 2014 11:48 pm

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#10 Postby Frank Green » Thu May 12, 2016 12:06 am

Willow, Your welcome! Your gun should hammer them just fine. Let me know how it works for ya!

I'm running the 180 Bergers at 2900fps. out of my gun. Barrel finish length is 32".

Later, Frank

macguru
Posts: 1258
Joined: Wed Aug 05, 2009 9:49 am

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#11 Postby macguru » Thu May 12, 2016 8:38 am

Re the 195s:
I have an 8 twist pacnor (new) and 8.5 twist kriegers (one old, one new as yet unchambered). There seems to be a nice low node a bit under 2800 and i am doing further testing on saturday at 800m. Last time i tried with the 8.5 barrel it let me down at 800 although it got possibles at 600 and 700. (at sea level) the 700 was not a great x count however. I am fairly confident the 8 twist will do a lot better at the longs, but if you are shooting at sea level i would not be confident an 8.5 will be enough, at least at this low (and legal!) node

more to follow (after saturday)

PS I am using 2213 in a SAUM. Low pressure, low recoil.

AlanF
Posts: 6779
Joined: Wed Jun 15, 2005 8:22 pm
Location: Maffra, Vic

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#12 Postby AlanF » Thu Jul 21, 2016 1:43 pm

Its been a while since any discussion about the SMK 183. Has anyone tried them? I've just bought a single box to try, probably after the QRA Queens.

DaveMc
Posts: 1429
Joined: Mon Aug 22, 2011 6:33 pm

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#13 Postby DaveMc » Thu Jul 21, 2016 6:08 pm

Thanks Rod for the measurements. Someone else miked a batch of the sierras for me at 0.2841 diameter so will be interesting batch to batch. Soo many barrels we see coming through now at 0.2843-0.2845 major diameter.

We have a few on the way to the store and hope to have them on the website on Monday. They might be a bigger advantage here in some states (limited by ME) than for Connaught (limited by BC).

ben_g
Posts: 32
Joined: Sun Apr 24, 2016 7:37 pm

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#14 Postby ben_g » Mon Jul 25, 2016 3:13 pm

Besides Frank has anyone else got any experience with the 183 in a 9 twist cut rifle barrel. Chamber will be 284win.

Cheers

Ben.

Rebel105
Posts: 586
Joined: Fri Jun 13, 2008 12:22 am

Re: 7mm bullets, 180 hybrid, 183 Sierra 195 Berger

#15 Postby Rebel105 » Wed Aug 24, 2016 1:13 pm

Alan & DaveMc, I have tried the 183's in a 8T barrel, nearly 200 now so the barrel is over the hump. I've not measured the barrel yet to determine if I have a bigger diameter, but so far with testing, I have found a place to continue testing but haven't finished doing the free flight tests. Down the range, I've tried from jam .015" to off .005" in a nut shell, if the free flight tests don't prove to be fantastic it's over to Bergers. I shot my SAUM with Hybrids last weekend to see if it was me, a 60.9 tells me it's not my technique so when I can I'll finish testing and report back. The bullet looks impressive but......
Geoff


Return to “Equipment & Technical”

Who is online

Users browsing this forum: Google [Bot] and 10 guests