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.243 Winchester 75Gr sierra HP
Mossbergboogie
Member Posts: 12,211
Hey there hoping someone can give me some insight on reloading.
Long story short I bought an OAL gauge for testing where I should seat bullets to get the correct jump.
I have a batch of Sierra 75gr HPs loaded to the specified 2.625 from Sierra. Upon checking the loads against the OAL measurement they are starting in or even jammed in the lands.
I have no signs of over pressure on fired cases but I am wondering why the Min OAL in the data was so close to the lands.
IS that even possible for a start min oal?
Long story short I bought an OAL gauge for testing where I should seat bullets to get the correct jump.
I have a batch of Sierra 75gr HPs loaded to the specified 2.625 from Sierra. Upon checking the loads against the OAL measurement they are starting in or even jammed in the lands.
I have no signs of over pressure on fired cases but I am wondering why the Min OAL in the data was so close to the lands.
IS that even possible for a start min oal?
Comments
I have never used your device. Take a trimmed fire formed neck size case and seat your bullet long. Use a candle or kitchen match to soot up the bullet. Chamber the round, extract. You will see exactly where the bullet is in the lands. Seat bullet deeper in case, re-soot the bullet - repeat test. When you can no longer see the marks in the soot seat the bullet a little more say 1/8 to 1/4 turn on the seating stem. Ready for test firing. Sharpie black isn't thick enough
Put your loads on paper. Keep track of the results.
Save the case as a guide for that bullet, other bullets will need their own guide. If you change between bullets, the guide will let you return to the correct setting quickly.
When seating bullets, I set them in about 1/2 way, lower the ram, spin the case 180 degrees, then finish seating the bullet - takes out 50% of the error in alignment.
Specification are general guidelines. That is why you have a starting load and a maximum load. Some rifles are done at the starting load, some can take handle more than the max. Tons of variables your barrel, chamber, lot of powder, bullets, primers, cases vs. the loading data.
I have never used your device. Take a trimmed fire formed neck size case and seat your bullet long. Use a candle or kitchen match to soot up the bullet. Chamber the round, extract. You will see exactly where the bullet is in the lands. Seat bullet deeper in case, re-soot the bullet - repeat test. When you can no longer see the marks in the soot seat the bullet a little more say 1/8 to 1/4 turn on the seating stem. Ready for test firing. Sharpie black isn't thick enough
Put your loads on paper. Keep track of the results.
Save the case as a guide for that bullet, other bullets will need their own guide. If you change between bullets, the guide will let you return to the correct setting quickly.
When seating bullets, I set them in about 1/2 way, lower the ram, spin the case 180 degrees, then finish seating the bullet - takes out 50% of the error in alignment.
Good advice above:
Take a look at a Sinclair 09600 bullet comparator which will do the 6MM/243. With care you can make one yourself. Compares off the ogive of the bullet. Once you determine the jump you need you can use the comparator for all the different style/weight 6mm bullets set at the same comparator ogive setting on your dial caliper.
What Model of gun are you testing?
You have to keep a heads up on some bolt action hunting guns.
You can mess around testing OAL accuracy and find that the gun likes a longer OAL than recommended in reloading manuals and your reloads are too long to feed from the magazine. Yours seems to be short chamber though (short OAL) and ok.
You will also find for hunting rifles at 100 yards that usually moving the bullet back and forth few thousands from what is recommended in reloading manual won't make over !/4 inch difference in the size of a group. Takes a real good shooter and several groups to prove ACCURACY difference in bullet seating depths of for example 0 to .025 difference. If the gun is shooting 1 inch or larger groups at 100 years you are just wasting time and ammo trying to make it a one holer, you need to look elsewhere for better accuracy first. Their are other things more important to produce accecptable accuracy first, such as glass bedding the rifle, proper powder/bullet combo and keeping your hulls matched for weight within about 5 gr's for a 243 and deburring the primer pocket holes inside. (Just to name a few things that are lots more important FIRST to start achieving accuracy from a gun) Notice I'm talking about hunting rifle not bench rest guns.
Also when finding the OAL using the trial and error, set your sizing die so as the bullet is held in the EMPTY HULLS (no powder or primer) with just a slight neck tension rather than full tight tension and do about 3 hulls, smoking the bullet with soot using a propane cigarette lighter on high flame and the bullet at the very tip of the flame is fast and can be easily wiped off for more test runs. If the bullet is tight in the hulls neck it will jam into the rifling too far.
If it's a bolt action you will have to reach finger inside and slightly hold the hull slightly sideways as it's being ejected.
It will take you few attempts and comparing the 3 or more bullets to get a good average OAL reading. Difference in neck tension will change the results.
Sounds kinda like you have a 243 with a tight minimum chamber.
(which is usually a good thing)
Welcome to the reloading and testing hobby. Be patient and enjoy.
I was just concerned that the book Min OAL was close or in the lands with that particular bullet. The v-maxs I have are much further out.
The loading does shoot MOA for the most part. Nothing special and I don't plan on shooting much over 150-200 with this rifle.
Thanks for any and all advice I am learning as much as I can sneak away into the basement to reload.
Good points and thanks, It's just a pos mossberg 100 I bought 3 years ago for under 300 dollars. Not going to be a long range shooter ever. I bought it just to get a start into the rifle cartridges. Shortages caused me to take up reloading.
I was just concerned that the book Min OAL was close or in the lands with that particular bullet. The v-maxs I have are much further out.
The loading does shoot MOA for the most part. Nothing special and I don't plan on shooting much over 150-200 with this rifle.
Thanks for any and all advice I am learning as much as I can sneak away into the basement to reload.
A lot a good advice here.
You may be surprised by the rifle. I paid $260 for a used Savage 110, chambered in 22-250, that regularly shoots 3 round groups under 1/2"......even with me shooting it.
If it means anything, I have been hand loading for about 10 years and still learn things in this forum.
My son bought a Sears (SEARS stamped on barrel of rifle)) 30 06 that was well used, stock was really ugly looking white wood with no grain at all pot metal floorplate all scratched up, made by Winchester for Sears, a Model 70, 30-06. I would not have give over $50 for the old beater looking ugly gun. The blueing was still good. I got to checking the ugly ducking in my spare time, headspace first, all ok everything tight and good, cleaned a dirty bore, installed a nice 3.5x10 leupold scope for group testing, the leupold scope looked like I had put lipstick on a pig, took the to rifle range with some of my favorite 06 reloads for a test, when I took another nice looking Win 70 xtr rifle I had just glass bedded. The XTR shot 1 1/2 inch group and showed promise of just needing little tuning of powder charge probably.
Up comes the ugly ducking, (made sure no one else was around to see the ugly gun with a Leupold scope attached) first two holes cut each other and the third was out by about 1/4 inch. What???
Let it cool while I shot the other again. Went back to the Sears Model 70. All three holes touched. I later (after installing onto a nice glass bedded stock) shot 9 continuous shots into a nickel size group and the 10th shot out by 1/2 inch. I usually don't shoot over 3 continuous shots out of a 06 but just had to keep going to see what 10 shots would do. This was feeding 3 shots at a time from the magazine. I was ashamed of myself for getting a good barrel so hot just to see if the group would open or ???
We now have that SEARS Model 70 action in a real nice stock, leupold scope and is a very accurate favorite hunting rifle.
Could not leave the gun ugly, because: LIFE IS TOO SHORT TO HUNT WITH A UGLY GUN[;)]
Never know until you test a gun.
Around 1960, I bought a used Winchester 70 varmint model in .243 for $72. Ordered a K10 Weaver from S. A. Wentling of Palmayra, PA. I had a batch of primers I got from the DCM (they were CCI 200). I got Herter dies and 2 boxes of new unprimed Rem. brass. Since 4895 powder was 75 cents a lb., I started with 40 grs. and Sierra 75 HP bullets. In all the years since, I've found no reason to change. I've shot a lot of crows and a bunch of woodchucks with that rig. I would imagine it will be for sale after I'm dead (but not before!).
$1 a pound for powder. Wow.$30 or more a pound now. Herter dies. Did the Herter dies fit in their press or use with small hammer or hand without the press.
Had a friend that had a Herter press, Took special shell holders.
Think maybe he also had a shell holder adapter for other shell holders.
I bought lots of H4831 and H4895 for $2/# in the 70's.
Long story short I bought an OAL gauge for testing where I should seat bullets to get the correct jump.
Around .025 jump is about right for a hunting rifle.
I've tested hunting rifles from 0 jump to .030 and usually not over !/4 inch difference in 100 yard groups for accuracy going from 0 jump to .100. Usually just go by the reloading manual for OAL is ok for hunting rifles.
If you want to keep your jump the same with different rifle bullets get yourself a Sinclair comparator, mentioned above in prev post.
Weatherby for one has long ogive chambers and not possible to seat the bullets out far enough for 0 jump and still feed thru magazine.
The long leade (jump) reduces chamber pressure.
What OAL gauge are you using?
I'm sorry this is so late but I've been moving half way across the country for the last few days.
quote:Upon checking the loads against the OAL measurement they are starting in or even jammed in the lands.
This because you are using a number generated by Sierra which measures from the tip of the bullet to the base of the case. Your comparator measures from the base of the bullet ogive to the base of the case. This leaves more of the bullet seated out of the case, therefore 'jamming' into the lands.
If this isn't clear, load an empty case measuring from the tip of the bullet to the base of the case. Then set this beside a case loaded with that same number using the comparator. The difference should be obvious.
Unless the load data specifies an ogive measurement, they are usually
referring to a true OAL or OVERALL measurement from the tip to the base of the case. These OAL numbers will often vary slightly depending on the tip construction and damage to the tips. That's the beauty of OGIVE measurements, they are more consistent.
I will add some more when I get a few more minutes...
Best.
Which were loaded prior to checking anything with ogive measurements.
I used the gauge and several bullets from the Hornady modified case and compared that measurement and the measurement of the loaded bullets the ogive on the modified case was 2.254, The loaded bullets are ogive of 2.259.
Which if i am doing everything right puts the bullet loaded to Sierra's data in the lands .005 thousands.
Another thing I haven't taken into consideration is the actual headspace of the rifle. May be 5-7 thousands more than that of the hornady modified case.
Correct me if I am wrong please.
Fire formed cases, neck sized only if you have a round chamber is the brass I'd be using.
If your soot marked bullets are showing that you are engaging the rifling after chambering and extracting the test round at your OAL then you are asking for High Pressures with that load IMHO. Keep seating deeper until the bullet shows no marks in fresh soot.
Fire formed cases, neck sized only if you have a round chamber is the brass I'd be using.
at your OAL then you are asking for High Pressures with that load
If you have 0 jump you need to be aware as Charlie says about possibility of High Chamber pressures.
Don't mess around and pull a Bubba and burst a chamber in your face!
ce.Use the soot test as suggested and keep seating the bullets deeper until you get about .025 jump or more. As mentioned above Roy Weatherby purposely chambered his magnum rifles with a long chamber leade (jump) to reduce excess pressures in his Magnum rifles.
You can review such online.