AR15.Com Archives
 Hmmmm moment while reloading today... Hornady#2279 75g BTHP
bubbleheadmike  [Member]
5/23/2013 11:39:31 AM
223 loading

After completing my load workup today, I tried to take my ogive measurement and wasn't able to, the fixture touched the case mouth before I felt that it stopped on the bullet.

case length 1.750
COL 2.250

I felt it was a deep seat, the bullet is massive compared to my 50-60g bullets....... hmmmmm......


any comments?

Thanks!!!
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peligro113  [Team Member]
5/23/2013 11:44:08 AM
Did you use the right size comparator

Those 75g hpbt I load to 2.365 but I use them in a bolt gun
Eric802  [Team Member]
5/23/2013 11:53:12 AM
Your COL sounds right, something must be goofy with the comparator.
Kujoe  [Team Member]
5/23/2013 12:38:58 PM
If I remember correctly, those 75gr bullets were not meant for an AR as they are too long.

I could be wrong, but I seem to remember something like that from a few years ago. I would call them if I were you.
Trollslayer  [Member]
5/23/2013 1:00:59 PM
Originally Posted By bubbleheadmike:
... the fixture touched the case mouth before I felt that it stopped on the bullet.

any comments?

Thanks!!!


You are not using the proper gage for the bullet you are attempting to measure. The gages are caliber specific.

Which gage are you using?
Trollslayer  [Member]
5/23/2013 1:01:31 PM
Originally Posted By Kujoe:
If I remember correctly, those 75gr bullets were not meant for an AR as they are too long.

I could be wrong, but I seem to remember something like that from a few years ago. I would call them if I were you.


You are incorrect. That is an excellent bullet for AR-15's, especially so, even when seated to magazine length.
Eric802  [Team Member]
5/23/2013 1:04:21 PM
Originally Posted By Trollslayer:
Originally Posted By Kujoe:
If I remember correctly, those 75gr bullets were not meant for an AR as they are too long.

I could be wrong, but I seem to remember something like that from a few years ago. I would call them if I were you.


You are incorrect. That is an excellent bullet for AR-15's, especially so, even when seated to magazine length.


You're thinking of the 75gr AMAX, that can't be seated to mag length.
Kujoe  [Team Member]
5/23/2013 2:42:54 PM
Gotcha, my mistake.
bubbleheadmike  [Member]
5/23/2013 4:19:06 PM
thanks for the replies....


I am using a sinclair comparator marked .22

I can hit the ogive on my 55g fmj, and my 60g vmax, but for some reason I can't hit it with these 75g hpbt
Trollslayer  [Member]
5/23/2013 5:51:41 PM
So, get your caliper out and make a few measurements. Is your gage mismarked? Is it bored over-sized?

Are your bullets under-sized? At what bullet diameter does the gage intercept the bullet surface?

You have the stuff in front of you. Use it. Work it out.
EWP  [Member]
5/23/2013 5:56:20 PM
Originally Posted By bubbleheadmike:
thanks for the replies....


I am using a sinclair comparator marked .22

I can hit the ogive on my 55g fmj, and my 60g vmax, but for some reason I can't hit it with these 75g hpbt


The sinclair comparator inserts are not meant to measure loaded rounds(it says this on their website), they are for sorting bullets based on shank length.

Their Hex comparator is made for measuring loaded rounds.

The insert comparators measure right at the ogive/shank junction and hit the case mouth on most loads.

I had to buy a caliber size under the bullet size I'm loading to use the Sinclair comparators on my loaded ammo, for 6.8 SPC I use the 6.5mm comparator and for 223 Rem you will likely need a 20 cal Sinclair comparator to measure on the center of the ogive.

You would be better off just buying the Hornady comparator inserts, I have those also and after using both I mainly just use the Hornady inserts now.

EWP
bubbleheadmike  [Member]
5/23/2013 6:19:06 PM
according the following Sinclair video, it should also work on loaded ammo.......

http://www.youtube.com/watch?v=3wlsgGKfjfI


regretfully I'm now at work and away from my reloading haven, but I will mic the bullets when I get home.....

as I said, I was able to take a measurement on 2 other Hornady bullets, all three are .224, but the mic will definitely answer why......


....so no one else has had the same experience......


Trollslayer  [Member]
5/23/2013 8:52:47 PM
Originally Posted By EWP:
Originally Posted By bubbleheadmike:
thanks for the replies....


I am using a sinclair comparator marked .22

I can hit the ogive on my 55g fmj, and my 60g vmax, but for some reason I can't hit it with these 75g hpbt


The sinclair comparator inserts are not meant to measure loaded rounds(it says this on their website), they are for sorting bullets based on shank length.

Their Hex comparator is made for measuring loaded rounds.

The insert comparators measure right at the ogive/shank junction and hit the case mouth on most loads.

I had to buy a caliber size under the bullet size I'm loading to use the Sinclair comparators on my loaded ammo, for 6.8 SPC I use the 6.5mm comparator and for 223 Rem you will likely need a 20 cal Sinclair comparator to measure on the center of the ogive.

You would be better off just buying the Hornady comparator inserts, I have those also and after using both I mainly just use the Hornady inserts now.

EWP


DOH! He wasn't even using the proper gage?
EWP  [Member]
5/23/2013 10:38:20 PM
Originally Posted By Trollslayer:
Originally Posted By EWP:
Originally Posted By bubbleheadmike:
thanks for the replies....


I am using a sinclair comparator marked .22

I can hit the ogive on my 55g fmj, and my 60g vmax, but for some reason I can't hit it with these 75g hpbt


The sinclair comparator inserts are not meant to measure loaded rounds(it says this on their website), they are for sorting bullets based on shank length.

Their Hex comparator is made for measuring loaded rounds.

The insert comparators measure right at the ogive/shank junction and hit the case mouth on most loads.

I had to buy a caliber size under the bullet size I'm loading to use the Sinclair comparators on my loaded ammo, for 6.8 SPC I use the 6.5mm comparator and for 223 Rem you will likely need a 20 cal Sinclair comparator to measure on the center of the ogive.

You would be better off just buying the Hornady comparator inserts, I have those also and after using both I mainly just use the Hornady inserts now.

EWP


DOH! He wasn't even using the proper gage?


Well they will work just not with some bullets, it depends on the bullet profile and how close the ogive/shank junction is to the case mouth when the bullet is seated.


It's better to have a comparator that reads in the middle of the ogive and not so close to the shank junction for loaded rounds, with that said though my Sinclair #22 comparator sits fine on my 75gr BTHP loads with an 1/8" gap between the comparator and the case mouth.

The one I had the most trouble with was the #27 comparator, it hit the case mouth on almost every one of my 6.8 loads so I had to get the #26 comparator and it works perfectly with all 6.8 bullets and reads in the ideal location on the ogive.

EWP
bubbleheadmike  [Member]
5/24/2013 10:54:04 AM
Thanks EWP


.....you got me thinking now that my tool may be out of spec?

I'll spend a few bucks and get the Hornady version...... wouldn't ya know, it's the only piece of Sinclair equipment I have, everything else is Hornady..... ;)


Thanks again!!!
Trollslayer  [Member]
5/24/2013 12:54:44 PM
It's unlikely to be out of spec. It is just not designed to be used for the measurement you are trying to make, so it's hole diameter is different.

The Hornady/Stoney Point gage works, for sure. Getting one of those is the right thing to do.
jlow  [Member]
5/24/2013 4:48:22 PM
This does not make sense. The only way the comparator can "touch the case mouth” is the diameter of the comparator is greater than 0.224” or the bullet is less than 0.224”. Now you say that it works with a 50-60 gr bullet so it must be smaller than .224 so you can see the two statements would appear to counter each other.

What I would ask you to do is to drop a 50-60 gr .224 bullet into the comparator and it should stop on the ojive. Now doe the same thing with the 75gr BTHP bullet and if you are correct in the above statement, it should not stop on the ojive but fall through. If this is the case, use your caliper to measure the diameter of the two bullets, the 50-60 gr one should be .224 and the "75gr BTHP” bullet will be significantly less. i.e. it is not a .224 bullet.
Trollslayer  [Member]
5/24/2013 7:41:23 PM
Originally Posted By jlow:
This does not make sense.


Something goofy is going on, that's for sure.

Unlike the Hornady gage, the Sinclair is cut with a throating reamer. This means the hole is tapered, reaching the bore diameter at some depth inside the tool. The Hornady tool has a bore diameter right at the entrance to the gage.

A 50 gr bullet seated to 2.250" OAL is not seated as deeply as a 75 gr bullet seated to the same OAL. The 75 gr bullet goes deeply into the gage because of this and because it is a more tapered profile than the 50 gr.

Neither bullet will fall thru doing the test you suggest. It's just that the Sinclair is not a straight-walled hole.

I don't know if I explained this very well. A picture would save me typing 1,000 words.
bubbleheadmike  [Member]
5/24/2013 7:55:43 PM
....at work again, don't have the numbers in front of me, when I use the comparator to measure just the bullet (non loaded) all 3 stop on the ogive and I get a reading on my caliper, natch, the comparator insert has to be smaller than.224.....

I know this sounds weird, that's why I'm asking.....

I measure a 60g Vmax COL 2.200" and I can see shiny bullet between the cartridge mouth and insert..... but when I insert one of my 75g HPBT COL 2.250" and the bullet goes far enough into the insert to the point where I can't see shiny bullet and it appears to my old eyes (with cheaters) to be touching or darn near touching the cartridge mouth....

at your mercy.....


added...... Trollslayer, somehow I missed your reply while composing the above, but what you say makes perfect sense to me..... has to be the "profile" of the 75g vs 60g..... kinda got me worried that I was seating too deep
jlow  [Member]
5/24/2013 8:14:11 PM

Originally Posted By Trollslayer:
Originally Posted By jlow:
This does not make sense.


Something goofy is going on, that's for sure.

Unlike the Hornady gage, the Sinclair is cut with a throating reamer. This means the hole is tapered, reaching the bore diameter at some depth inside the tool. The Hornady tool has a bore diameter right at the entrance to the gage.

A 50 gr bullet seated to 2.250" OAL is not seated as deeply as a 75 gr bullet seated to the same OAL. The 75 gr bullet goes deeply into the gage because of this and because it is a more tapered profile than the 50 gr.

Neither bullet will fall thru doing the test you suggest. It's just that the Sinclair is not a straight-walled hole.

I don't know if I explained this very well. A picture would save me typing 1,000 words.
That could well be the problem.

I went and measured the diameter of the hole in the Hornady comparator and it was around 0.2120-0.2125” (for a .223 bullet). You probably will not be able to do the same with the Sinclair if it is tapered as per Tollslayer comment, but if you drop the bullet in the Sinclair, you will be able to see how far down it drops and how much of the bullet bearing surface sticks out and that would be your answer. If you check with a caliper how far down 0.2125” is on your 75 gr HPBT, if the area is above the bearing surface you will know that it will or not work.

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